Since you're from the "local" area (Belgium), do you happen to know why the numbers have declined over the years? From this article [1] it seemed like it was hugely popular pre-WWII (3,750) with that article quoting 500 in the modern era.

Less acceptable currently, other alternatives? Still seems famous and popular, just not quite as much as it used to be.

[1] https://en.wikipedia.org/wiki/Geel#A_model_of_psychiatric_ca...