Further, an analysis using cumulative statistics from 1984 to February 2009 indicated that the major age groups for HIV infection are 20-29 (38%) and 30-39 years (35%). Of all those infected, 91% are males and 9% females, for a ratio of infected males to infected females of 10.6:1. In addition, 36% of all those who are infected are unemployed. The numbers contracting HIV were concentrated in several risk groups, including 6,053 IDUs (36%), 5,337 homosexuals (31%), 4,078 heterosexuals (24%), and 1,257 bisexuals (7%) (Taiwan CDC 2005) .