Apps are a terrible way to gauge the number of cops and medics since the process weeds out a lot of people before they get to the test, and even then a chunk fail, my go to example is my original deputy class in late 2016/early 2017 had like 20 people and that week the APD probably inducted a solid 60 deputies. There's only me and one other person left and the other dude is a senior, that would mean after 2 years there's over a 90% attrition rate.
APD/Med is more plug and play style than civ where everything takes time and money and you can't just pop in and pop out easily. There's not much that can be done about that but once you factor in Olympus having 333 player slots at peak times and a playerbase of 10,000 people whitelisted factions are the minority most of the time.