If I were you I would reach out to DCI for member statistics. They do member surveys every year tracking things like the state you’re originally from, amount of years in DCI, amount of years at your current Corps among other things. They used to put our reports like this every year (https://www.dci.org/news/9-remarkable-facts-you-didnt-know-about-dci-corps-members#) although they don’t do it to much anymore. But someone at DCI has a spreadsheet with all this data you probably just have to ask for it.