Thanks Aaron. As I am sure as everyone has already seen this morning we have some additional exciting positive news on top of our strong first quarter financial performance. I will spend most of my time talking about our acquisition of Callcredit in just a moment. First let me quickly highlight our strong start to the year extending the momentum we've had over the past three years. Our teams continue to execute against our strategies and deliver growth well above the underlying markets in which we operate. Once again revenue grew double digits for the total company as well as for each of our segments, similarly adjusted EBITDA and adjusted EPS both increase significantly. In the segments USIS’ performance was outstanding driven by ongoing strength in financial services in health care and in particular we continue to see exceptional results for credit vision and credit vision link, we believe that our suite of ever evolving trend of products has many years of substantial growth still to come in the US alone. In international we continue to see very strong growth in India in January across our global footprint, notably we saw modest revenue growth in the quarter in South Africa. Last year we invested in our technology infrastructure there. This allows us to reduce cost by fully moving [indiscernible] our final legacy mainframe at the same time the technology platform will facilitate the efficient lift and shift of the innovation and capabilities that should stimulate our long term growth there. Seeing South Africa return to growth this quarter is a good sign that the business is starting to stabilize and is heading in the right direction. And finally in consumer interactive, I'm pleased to announce that we recently signed another strategic partnership agreement, this time with American Express. American Express will leverage our crediting dashboard branded as American Express, my credit guide to provide all consumers free access to their credit information, this includes their credit report credit score, factors impacting their score, credibility to help identify identity theft as well as educational tool such as our credit score simulator to improve their financial health. American Express will benefit from a new channel for effectively engaging with existing customers and acquiring new ones. We are very excited about this new strategic relationship in our core financial services market. Taken together our first quarter performance reflects our strong business model that broadly leverages data assets and capabilities across our organization to help us realize strong revenue growth with good incremental margins. While this approach certainly contributes to our strong financial performance, it has also created a more sustainable and diversified growth profile that we believe can deliver relative outperformance through cycles. We are off to a solid start in 2018 and expect to have another very good year. There's no doubt the TransUnion has never been stronger that puts us in an ideal position to make acquisitions that help make a great business even better and position us for outstanding long term growth. Before I delve into the details of the acquisition, I think it makes sense to spend a minute on our successful acquisition strategy and how it has played a key role in our growth over the past 5 or 6 years. We have focused on three key strategies with our acquisitions and I've often found transactions across two or even all three of them. First, we invest in unique and differentiated data assets that can augment the core contributory credit data that we receive in virtually all of our markets that this allows us to create new valuable offerings for our customers while leveraging existing data assets. We've made a series of very successful acquisitions around data going back to late 2013 we bought TLO which utilizes public records data for identity authentication, fraud prevention and debt recovery. We've seen tremendous growth in margin expansion over the past four years and expect additional growth in the future. About a year later we bought LTC, the said asset delivers predictive analytics using alternative data and has been instrumental in the development of credit vision link and other alternative data offerings. In late last year, we have made another alternative data related acquisition with FactorTrust, one of the largest players in the short term lending market. They are essentially a credit bureau for this market and have data on more than 20 million consumers who don't typically show up in the data we receive from traditional lenders. It's more robust view of borrowers as they're called will help us develop the next version of CreditVision Link and enable many other products for our customers. FactorTrsut also expands TransUnion's reach into the short term lending opening a new fast growing market to the breadth of TransUnion’s credit and non-credit risk information solutions. Our second strategy focus is on acquiring new capabilities to expand in our vertical markets. In the healthcare vertical, we bought eScan in late 2013 and that asset is the foundation of our highly successful fast growing coverage discovery business. In 2016, we augmented this business with audits and Auditz and Rtech each of these both arms has provided valuable data that improved our matching algorithms and thus improved our yield. In the insurance vertical, we completed the acquisition of Drivers History in April of 2016 and data DataLink Services in August of last year, together these businesses will allow us to offer a product that pre-screens auto insurance applicants and then seamlessly purchases and incorporates costly motor vehicle reports only when appropriate. We see opportunities to utilize this data in employment screening, data screening collections government and other parts of TransUnion to provide valuable insights of our consumers. Most recently we acquired eBureau which provides rapid development and deployment of custom models and financial services collections and fraud. eBureau has a very broad applicability across virtually every part of TransUnion both domestically and internationally. It is the type of core capability that can drive significant cutting edge innovation. Finally we want to continue to expand our international positions and obviously Callcredit fit squarely into the strategy. Before I come to that, let me remind you about two other international investments that have worked well and give us increased conviction in our ability to successfully add another bureau asset to our portfolio and to run the TransUnion strategic playbook. Going back to 2001, we have partnered with a number of large Indian banks to form CIBIL the first and largest credit bureau in India. We are on 27.5% on CBIL until 2014 when began to aggressively by the equity leading to our current status of 92%. The investment continues to pay off handsomely. India is now our second largest international market and accrue constant currency revenue 24% in 2016 and another 32% in 2017 and we see a long growth path in front of us as the macroeconomic situation is excellent. On top of that we continue to bring innovation into the market with products like CreditVision, CreditView decisioning and more. In February of 2016, we acquired one of the two bureaus in Colombia. We have improved their technology product platform, introduced pricing analytics and products like CreditVision while also bringing new talent to the organization to support our growth plans. After just two years we tracking all of our plans and seeing value creation from the acquisition. And that brings us to Callcredit which is one of the three bureaus in the attractive UK market. I will walk you through the market and the business in just a moment but I want to start with the conclusion. Callcredit is a truly outstanding acquisition for TransUnion, high quality credit bureau assets like Callcredit are scarce of the opportunity to acquire a strong growing foothold in the second largest credit market in the world, there is a win for TransUnion. Callcredit is the second largest and fastest growing bureau in the UK but differentiated assets and technology and candidly there are many parallels to the TransUnion story from 5 or 6 years ago when we consider where the industry is, how the company has evolved and the potential to more fully leverage the core assets of the business through innovation. Similar to TransUnion Callcredit has leverage data and technology to deliver the unique solutions to its customers leading to outsized growth. There is a view that inefficient market assets ultimately find their way to the right owner and I'm absolutely convinced that TransUnion is the best owner for Callcredit. The marriage [ph] of our global capabilities and proven track record of driving growth in international markets with a differentiated position Callcredit and their team has built in a large growing market will contribute to our long term growth equation. We spent considerable time with the Callcredit team and found a strong cultural fit, the team has done an outstanding job in building Callcredit and this is a second largest and fastest growing bureau in the UK. We have great confidence in TransUnion's ability to add value to an already attractive asset. Let me highlight three key dimensions of the acquisition that give us great convection and Callcredit will contribute to the TransUnion’s long term top and bottom line growth. First the core market has experienced underline growth of about 11% per year driven by increased loan volumes and that is expected to continue. The key component of this expectation is the growth of introduction of some of the important trends we benefited from in the US driven by the rapidly expanding digital economy, we are seeing the emergence of fintech lending, fraud solutions and trended data. TransUnion knows how to win in these areas and we have demonstrated the ability to lift and ship products and capabilities to capitalize upon or drive these trends in markets around the world. An example, the Canadian market is at a similar level of maturity as the UK and we've been able to deliver strong above market growth there. In fact we grew constant currency revenue 14% in 2017 and 20% in 2016; this was accomplished in large part by gaining share or expanding the market with innovations like CreditVision and Creditview and extending into new verticals like insurance. All products that have the applicability in the UK. Second, Callcredit has already been outperforming the underlying market and taking share through superior data and technology. This is a high quality asset that only get better as we leverage our global enterprise model and capabilities. Third, we believe there is a meaningful opportunity to optimize the organization and the cost structure of the business just as we did in our own international segment in 2016, we can unlock value by leveraging our global scale and enterprise capabilities. But fundamentally this acquisition is about driving long term growth and leveraging an incredible set of assets and people, there's no doubt that we can improve the margin structure over time. In fact by leveraging our global scale and IP, we expect to realize at least 50 million of cost synergies by the end of 2019 and another 15 million after that. This meaningfully changes the margin structure and the implied valuation of the transaction before contemplating the substantial benefits we will see from revenue growth. Now let's walk through some of the details behind the transaction, starting with the market. By way of background the UK is the second largest Creditview market in the world however Callcredit also plays in adjacent spaces outside of the traditional bureau market taken together, all of Callcredits markets have an addressable market of about 2.4 billion that market grew and an 11% CAGR from 2014 to 2017. Going forward, we expect that total market growth to accelerate slightly driven in large part by strong double digit growth in fraud and decisioning and analytics. The regulatory environment is changing with open banking and general data protection regulations or GDPR. These will be implemented in 2018 and are focused on increasing competition among banks and enhancing consumer privacy rights. They will likely have a neutral to positive impact on our industry as the regulations will drive higher compliance standards and the need for new products among lending institutions. Based in leads, Callcredit is the fastest growing credit bureau in the UK; we estimate that 2017 revenue is approximately 190 million with EBITDA of 63 million. In recent years Callcredit’s EBITDA margin has remained relatively stable at about 30% and the company made significant investments to drive future growth and margin expansion which I will touch on in a moment. While the top of the market is consolidated, Callcredits are the broad base of more than 3,000 customers including the largest financial institutions as well as attractive high growth segments such as alternative finance digital commerce and the public sector. For the past several years, Callcredit has made some important improvements to their business, first they invested heavily in technology to move to a cloud based platform. This has contributed to their market share gains and will enable margin expansion as the company now is industry leading data quality and reliability. Callcredit also brought in new management including many industry experts like their CEO Mike Gordon. This team has done an outstanding job of improving Callcredit’s market position and product pipeline to deliver strong growth. Callcredit is organized around five units; credit services, fraud, decisioning and analytics, marketing services and consumer. Let me walk you through each of them call. Callcredit’s core credit services business represents about half of the company's revenue and they have roughly 32% share of this market. Creditservices leverages Callcredit’s data assets which cover 99% of the UK population to provide traditional credit reporting solutions, portfolio review and monitoring and collection services while the three credit bureaus in the UK operate with data parity, Callcredit has taken a leadership role in the market base on advantages and an income data technology and security services and a leading position in finech lending among the bureaus. The unit also has a market leading affordability assessment tool that analyzes historical consumer behavior and indebtedness to help customers make better lending decisions and comply with regulations. Credit services grew about 7% per year from 2014 to 2017 driven by share shift in banking both with new customer wins and incremental business with existing customers. At the same time like TransUnion, they seen substantial growth in alternative lending for Callcredit also has a market leading position. Callcredit has routinely won head to head comparison and thus new business on the strength of unique data gained from alternative lenders and their superior matching capabilities. Along with cutting edge technology, these are true differentiators in the marketplace, in fact Callcredit recently gained the primary position as three of the major banks and has additional large opportunities in the pipeline. Based on customer feedback, we believe that the market is ready for new products like Creditvision which has the potential to consider really accelerate growth on the top of the strong underlying market trend. There is also a sustained trend toward multi-bureau usage which is still nascent in the UK that should continue to open the door to increase volumes and non-bank customers like utilities and telcos are using more credit information to manage customer and channel risk. Finally, there is a growing demand for new products like Affordability and ID checks. Moving to the second largest business unit about one-third of Callcredits revenue comes from its fraud business which has grown strong, double digits from 2014 to 2017. Callcredit is a market leader in fraud and identity solutions as a result of an array of quality point solutions. We see a real opportunity to strategically bundle these point solutions into a comprehensive suite of products as we've done at TransUnion when we created ID vision. On top of these product related opportunities, the market is growing rapidly and is expected to grow even faster at about 20% per year for at least the next three years as the mobile digital economy continues to grow. Rapid growth in the number of online transactions products becoming more prevalent even as consumers expect more frictionless interactions and are more concerned about fraud, at the same time regulators are requiring greater levels of oversight to combat this problem. Callcredit entrenching and can capitalize on this trend by leveraging valuable data assets, sophisticated analytics and superior technology. We believe we are extremely well positioned to benefit from the underlying growth in the UK the same way we are currently benefiting in our other markets and just like credit services we should be able to outgrow the market given Callcredit and TransUnion leading capabilities. Running on Callcredit portfolio are relatively small decisioning analytics marketing and consumer business units. The decisioning and analytics business unit includes decision engines, a suite and criteria scores and workflow tools among other products. The marketing business is focused on database management enhancement and the consumer business has direct to consumer brand called [indiscernible] products used by a number of banks and lead aggregators that I referenced earlier we have been ruling out our direct to consumer solution credit view internationally in recent years and will do the same in the UK. With that overview done, I'm going to end where I started. With this high level view of why this is such an exciting acquisition for TransUnion, so to recap Callcredits sits as an attractive growing market but a long term trends are pointed in a positive direction we have the opportunity to bring meaningful innovation and capability to the market just so as we've done in Canada, Hong Kong, India Colombia and other international markets and finally we can optimize the cost structure of the business to expand margins over time. Clearly, we're very excited about Callcredit and I believe it will create significant shareholder value, at the same time we continue to pursue other smaller acquisitions that can also have a real impact on our business. I'm confident that our systems and employees are more than capable of integrating additional transactions that they come and that these will fit just as nicely with their clearly defined acquisition strategy as Callcredit and all the deals that have preceded it. Now I will turn the time over to Todd to first provide a few more details on the Callcredit acquisition. He will then walk you through the financials and provide you with updated guidance. Todd?