So I’ll take that, Doug. Yes, so right now because of COVID impacts, we've started the year, roughly we thought we were going to deliver about 140 aircraft this year. They are predominantly Lot 12 airplanes, so that's the first lot of our block buy. So right now, the team is forecasting rough numbers 120 to 125. It's still a little bit in flux, but that's our outlook right now. Right now based on what we're seeing and working with our supply chain and working with our production operations team, we're out looking roughly 140 aircraft deliveries out in 2021. We think based on the demand we have with Lot 12, 13, 14 and ultimately I talked about the Lot 15, production lot order that we're hopeful we'll get at the end of this quarter, we see about 169. So let's just round up to 170 aircraft delivered out in the 2022 time period. And then out in 2023, we see similar about 170 aircraft. That's basically predicated on the United States government program of record. Earlier year, we had some to your point congressional adds, but we're not assuming any congressional adds at least today once you get beyond 2021. There is still pent-up demand with our partner countries, our FMS customers demand. And then as you stated Doug, out in that time period, there are other interests for the airplane with our partner countries, existing FMS countries and there are some new potential FMS countries that potentially will buy aircraft, but it'll be beyond the 2023 time period. So I think we have a pretty good handle out to about 2022, 2023 where we think our production is going to be. Regarding margins, it really comes down to the PBL. Right now just based on how the customer is buying, sustainment they are, it is dilutive to the overall F-35 portfolio. Where we do see opportunities is in production. We do think if we continue to perform, continue to weed out inefficiencies and hopefully negotiate a deal where the customer rewards us for that. There is production opportunities, but it comes down to the PBL. And we do believe, we are starting to get more and more interest from the customer for a PBL or performance-based logistics concept and that would have us taking on investment as the industry taking on investment risk and it would then give us the opportunity assuming we perform and hit the service level agreements we'll sign up to -- for that to be margin-accretive.