Population Reference Bureau's 2006 World Population Data Sheet contains the latest population estimates, projections, and other key indicators for more than 200 countries, including births, deaths, natural increase, infant mortality, life expectancy, urban population, HIV/AIDS prevalence, contraceptive use, land area, percent of population living below $2/day, and population per square mile. New for the 2006 Data Sheet are data on net migration rates, percent of surface area protected, and population with access to improved sanitation.