Erich,

One starting point, although showing 2005 data is:http://bjs.ojp.usdoj.gov/index.cfm?ty=tp&tid=76

It cites:
During the 2004-05 school year, the 750 agencies surveyed had more than 25,000 full-time employees, including about 13,000 sworn personnel....These findings are based on the 2004-05 survey of Campus Law Enforcement Agencies (CLEA).
My recollection is that there are magazines aimed at the campus PD community and the best place to start would be your own campus PD.

If you fail PM and I'll ask two friends who are on campus.