Conversation so far:
how many religions are in the world today
According to some estimates,there are roughly 4200 religions in the world.
which is the largest religion
Christianity is the largest religion by population.
how about the smallest religion
Rastafari, with 0.6 million adherents
where are buddhists on the list of religious populations
Buddhism is the fifth largest religious population.

Question: how many categories are on the list
Self-contained rewrite: how many categories are on the list of religious populations