Regular proof sets are minted at the San Francisco facility. A proof half would also have a "S" mint letter. I'm not 100% sure but a lot of the late date halves were only issued in mint sets. You didn't get skunked anyway with that 40% Kennedy. Thanks for sharing.
Good Luck!
I have been asking all the banks I visit on how a box of halves can be obtained and they all say it can not be done. Let me know how to go getting that much. I do obtain small amounts ,but not very often from banks.
Wagbert is correct and 2009 Kennedy proofs were only minted at the San Francisco mint. However, if I recall correctly Kennedy halves were not released into general circulation starting in 2002. They were still produced to meet the demand of the collector market and were sold in rolls and bags to collectors at a premium above face value. So even if it's not a proof, it's still a coin that wasn't released by the mint into circulation. Good find!
I'll take the advice and conclude its definitely not a proof. Like I said, it was a first for me and thought it was. Thanks for setting the record straight!