The series comes from the 'Current Population Survey (Household Survey)'
The source code is: LNS11327660
Source: US. Bureau of Labor Statistics
Release: Employment Situation
US. Bureau of Labor Statistics, Labor Force Participation Rate: High School Graduates, No College, 25 years and over [LNS11327660], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/LNS11327660/, July 29, 2015.