Oops, my bad and my apologies. I admit i'm a bit touchy on the subject.
I've got that number from a book about slavery in our times and from an article in the newspaper i read (which is usually very reliable and probably one of the last newspapers which doesn't resort to "entertainment"). Since both figures were about the same i figured it's save to assume they're about right. But of course, one should never assume, so those numbers could be wrong.

But even Swiss law enforcement officials say that in Switzerland alone there are between 1000 and 2000 women who are forced into prostitution.