How many Buddhists, Taoists, etc. are there in Taiwan?
First of all, is there any way to answer this even in principle? I’m thinking particularly of the problem of estimating the number of followers of Buddhism or Chinese folk religion. (Some people may think they are Buddhist but worship Matsu, or think they are atheist but worship their ancestors, or maybe they have six religions at once.)
Then, do we have any way of knowing the answer? Like, estimates of church and temple participation, census information, poll results, etc.? I would assume the Christian population is easiest to estimate. I think there is some kind of government body which regulates religion, I saw a pamphlet from them.
The reason I ask is I recently learned about Yiguandao (One Unity Religion), which says they are the third largest religion in Taiwan, with over a million followers. This means one out of twenty people–but that doesn’t ring true. So, is there any concrete information?