What is the hardest regional to win RCA at

[New Lightning]

Based on this tread http://www.chiefdelphi.com/forums/sh...ight=Chairmans I started to wonder not who the top teams in each state but instead:

What is the hardest regional to win RCA or EI at? From my own research on tba here is what I found about my Old team's (1987) two regionals and my new team's (3792) regional and here is what I found:

Greater Kansas City:
RCA: 16
E.I: 16

St. Louis:
RCA: 10
E.I: 8

Hub City:
RCA: 7
E.I: 7

Based on just these three regionals its obvious to me that some regionals might be easier to win RCA and E.I. than others. My ultimate question is where is the toughest.