The series comes from the 'Current Employment Statistics (Establishment Survey)'
The source code is: CES6000000003
Source: US. Bureau of Labor Statistics
Release: Employment Situation
US. Bureau of Labor Statistics, Average Hourly Earnings of All Employees: Professional and Business Services [CES6000000003], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/CES6000000003/, August 2, 2015.