The series comes from the 'Current Population Survey (Household Survey)'
The source code is: LNU02000093
Source: US. Bureau of Labor Statistics
Release: Employment Situation
US. Bureau of Labor Statistics, Employment Level: 45 to 54 years [LNU02000093], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/LNU02000093/, July 5, 2015.