Federal civil servants earned average pay and benefits of $123,049 in 2009 while private workers made $61,051 in total compensation, according to the Bureau of Economic Analysis. The data are the latest available.

The federal compensation advantage has grown from $30,415 in 2000 to $61,998 last year.

Public employee unions say the compensation gap reflects the increasingly high level of skill and education required for most federal jobs and the government contracting out lower-paid jobs to the private sector in recent years.

“The data are not useful for a direct public-private pay comparison,” says Colleen Kelley, president of the National Treasury Employees Union.