The World Factbook, United StatesCentral Intelligence Agency (GDP (PPP), labor force and unemployment rate). Accessed on March 30, 2012. Note: The GDP (PPP) per person employed was calculated by dividing the GDP (PPP) by the employed population. The employed population was obtained by subtracting the unemployed population from the labor force. The unemployed population was calculated by multiplying the unemployment rate by the labor force and dividing the result by 100. The GDP (PPP) per capita was calculated by dividing the GDP (PPP) by the total population.