I could not find any recent comparable numbers for the US but these seem to tell a tale:
“Staff working in the private sector took an average of 6.4 days off last year, down from 7.2 days the previous year, while absence rates among public workers only fell marginally, from 9.8 to 9.7 days.”
http://www.telegraph.co.uk/news/uknews/5863545/Private-sector-workers-taking-fewer-sick-days.html
And there was another blow for public sector workers when it was revealed the average civil servant takes 11 sick days a year — almost double the rate of absence in the private sector.
When you crank in the cops and firemen (public sector workers) that’s going to balloon the sick days taken.