Here's a blurb I found on Wiki:
The number of "Taoists" is difficult to estimate, partly for definitional reasons (who counts as a Taoist?), and partly for practical ones (it is illegal for private parties to conduct surveys in China). The number of people practicing some aspect of the
Chinese folk religion might number in the hundreds of millions. (Adherents.com estimates "Traditional Chinese religion" at nearly four hundred million). The number of people patronising
Daoshi (Taoist "priests" or masters) would be smaller by several orders of magnitude, while the number of literary
Daojia would be smaller yet. At the same time, most Chinese people and many others have been influenced in some way by Taoist tradition.