First, and most importantly, we caution against comparing any of our products to prior vintages. Products are updated every year with the best available data and methods so it is entirely possible that high variability exists when comparing vintages due to changes in data sources or methodology. The change in the variable ALC_2_AV are due to changes in methodology and how we created our predictions for the 2019 CommunityHealth product. It is very likely that there will be changes across the board on a number of variables. This is why we do not recommend comparing vintages.