Censuses provide population numbers, household or family size and composition, and information on sex and age distribution. They often include other demographic, economic and health-related topics as well.  

The 1999 census, the sixth in Kenya's history, is a de facto census which collected data through face-to-face interviews. The census days were August 24-25, 1999. Questions on literacy, occupation, work status, and date of death of last-born children were not repeated from the previous census; however, questions on duration of residence, education attainment, and total children ever born, as well as household questions on dwelling units and number of occupied rooms were added.