What are the chances of HIV/AIDS being transmitted through a condom during ?

A long time I heard that the chances were 1 out of 100, 1%. Well if you've been having with hundreds of prostitutes, then the chances of catching it are good. I've read different things: in the book Brothel, the author writes how there are no reported cases of HIV/AIDS being transmitted through a condom during with one of the legal prostitutes there, but then I've read that the incidence of HIV/AIDS in Asian prostitutes is as high as two-thirds. That could be because they are having unprotected , though. So if you are always careful and always use a condom, what are the odds?