Hi, Bill. So, first, just from a seasonality perspective, where our year kind of goes right as we have higher spend in the back year than we do in the front of the year primarily related two of our events that take place, our convention in July each year, last year, we had about 10,000 people there. So, pretty big event. We also have something called our International Leadership Advancement Trip, which is a recognition and training event that gets expense in the back-half of the year to third and fourth quarter evenly. The event takes place in the following year. So we always have a high amount of spend in Q3 and Q4. What was unique about this year is that in Q4 we've been implementing a new ERP initiative, which we said we'd spend approximately $7 million in 2019. We spent slightly in excess of $7 million last year, and in 2019, that was all flow through directly to expense. There was no capitalization of the implementation based on the accounting rules in place for 2019. The accounting rules that are going in place for 2020 to allow you to capitalize that and while we expect to spend about $2.5 million in 2020, it'll -- only about $500,000 will actually hit the P&L in 2020. So, we'll get some leverage there for sure. So think of that as kind of a one-time expense hitting last year that will benefit us for a long time. A couple other areas from a headcount perspective, we have increased our employee base to support clients and our distribution centers to support growth. So, labor on a year-over-year basis is also uniting to point out as far as an increase, and they're largely the key items, the rest is variable. So, when you think commission, that's our largest expense, SGA expense, and it's really completely variable with the business. So that of course would grow as the business grows, but we view the percentage of commissions to be about the same, and how we pay compensation really it is -- doesn't have to do with your tenure, it has to do with your activities, so, we kind of think that will be somewhat consistent year-over-year. Other items of variability are things like shipping, and things like transactional fees, credit transactional credit card fees, and our call center is an outsourced operation. So that is somewhat variable as well as the call line fluctuates. So hopefully that answers your question.