Our Maryland state residents association, MaCCRA, gathers information each year about percentage increases and makes that information available to the MaCCRA members. There are some complications because not all CCRCs have the same fiscal year, and the specifics differ a little from one community to another. But gathering this information would be a natural way in which NaCCRA could provide valuable data from around the country in one place.
Also, as a caution, the size of a rate increase is affected by many factors in each situation and time point, so it's only one data point in a larger picture. That said, it's still valuable to see the general patterns, and even more valuable to observe trends over several years. In Maryland, we have percentage increase data data from the last 5 years.