Different geographic areas have very different shares of infected sexually active men and women. In addition, the share of people infected with HIV is conditioned by belonging to different behavioural groups. In general, the risk increases with the number of sexual partners and unprotected sexual encounters. In short, the more sexual partners you have the more likely you are to encounter an HIV-infected person, and the more unprotected sexual intercourse you have with such a person the more likely you are to become infected.