How many witches are still alive?

It is difficult to count the number of Witches out there, because people would not tell if they practice Witchcraft when there is a negative stigma against people who practice Witchcraft.

In North American Paganism (Wicca, Voudon, etc) are recognised religious paths and there are thousands of practitioners who are "out of the broom closet".

Wicca is a new age interpretation of ancient paganism (and not a very well thought out one). Though there are thousands of "practitioners", it isn't accurate to refer to them as witches, wether they call themselves that or not. There are also thousands of idiots that drink blood and skulk around in dark clothing pretending to be vampires, it doesn't make it true. Witchcraft DOES NOT EXIST, so there ARE NO WITCHES. Simply believing something doesn't make it true.