https://www.forbes.com/sites/andrewbiggs/2018/12/14/the-federal-employee-pay-penalty-31-less-than-state-and-local-government-workers-really/
https://fcw.com/articles/2017/10/05/federal-workforce-volker-size.aspx
https://www.payscale.com/research/US/Employer=U.S._Postal_Service_(USPS)/Hourly_Rate
https://www.opm.gov/