Source: U.S. Bureau of Labor Statistics
Release: Employment Situation
The series comes from the 'Current Population Survey (Household Survey)'
The source code is: LNU03032224
U.S. Bureau of Labor Statistics, Unemployment Level: Construction and Extraction Occupations [LNU03032224], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/LNU03032224, December 15, 2017.