From The US Bureau of Labor Statistics.
The US unemployment rate was 4.3 percent in May 2017, down from 4.8 percent in January. Among the unemployed, the number of job losers and persons who completed temporary jobs declined by 211,000 to 3.3 million in May, or 2.1 percent of the total labor force. In comparison, job leavers made up 0.5 percent of the labor force. These are people who quit or voluntarily ended their jobs and began searching for a new job.
Unemployed reentrants to the labor force made up 1.3 percent of the labor force in May 2017. Reentrants are people who previously worked but were out of the labor force before they began their job search. Unemployed new entrants made up 0.4 percent of the labor force in May.
These data are from the Current Population Survey. For more information, see “The Employment Situation — May 2017″