Sure. So I think it's easiest to sort of separate our revenue portfolio between what are stable end markets and what are sort of discretionary end markets. The stable end markets have consistently sort of grown through 2019 to now at very modest rates, call it, 2% to 3%, whether it's medical, personal care, et cetera, those kind of markets.
But there was a dislocation that even in those markets, there was destocking last year that played out, depending on the market 1, 2, 3 quarters to sort of finish their destocking in those markets. And then they've reconnected back to sort of demand and are growing again, which is true for this year, medical being sort of the worst, ag and medical being the most stable markets that had the biggest destocking because of fears of not having inventory in '21 and '22.
On the discretionary markets, as everyone knows by looking at housing data or automotive build data, well, harder to see it but appliances, electronics, et cetera, same story. Demand is, relative to 2019, not great. We're at a 28-year low in existing home sales in the United States. B&C construction in China is off dramatically, still -- and also a lot in Europe. So B&C prior demand is extremely challenged.
When you think about the materials world, existing home sales to something -- to Eastman is more important than new homes, because of all the appliances, electronics, more painting, et cetera. So that market is very challenged. It will come back. It's obviously, I don't think coming back this year, but that's upside to getting back to what is normal from where we are now and then growing from there. So there's a pretty big gap there relative to '19.
When it comes to auto, same thing, there's a huge backlog of increasingly older cars that need to be replaced around the world. And first is semiconductors limiting the ability for consumers to buy cars, then interest rates now slowing down the rate of buying cars, but the demand for that will certainly recover and be a significant amount of upside for us. Same thing with durables, big shift to service lifestyle post COVID. At some point, people rebalance back to some blend of buying material, discretionary items and seeing Taylor Swift.
So I think that all those are still well below sort of '19 levels in one form or fashion relative to where they should be. So as you look at this year, and the way our guidance is built, all we have is a lack of destocking, some innovation-driven growth, starting to deliver real value out of methanolysis, stable markets being okay.
And all that recovery that I just described is upside to '25 and '26. I'm not about to tell you which year it's going to happen, but there's certainly a lot of upside in places that are most challenged are also our highest value markets from a margin per unit basis. So as those markets went down, it was a significant headwind. As those markets come back, it's going to be a significant tailwind.