Someone a few posts back mentioned that different communities have different O-4 screen rates. If you want the most recent rate for any one community check this site out. It breaks it down by community and even by pilot/NFO. This will list all URL communities rates for the FY '07 O-4 selection board. FY '06 rates can be found here. I find that being familiar with the NPC site helps me find these tidbits of info when I wonder about things...