Off topic: Numbers of Internet engineers/operators

This is probably off-topic for the list, so I apologize. I'm trying to find some numbers (surveys, etc) that show the numbers of network engineers and operators (ie operations people, network engineers, network architects, possibly systems engineers, sysadmins, etc--for both Internet and/or intranet networks) that are working on the Internet today and maybe projections for the future. Numbers on personnel shortages would be good, too. Thanks for any references you can give me. Pete.