starflex3,
With the possible exception of Las Vegas (always a draw), the venues don't have much influence on numbers. Though Anaheim tends to be a popular venue for military shows (allowing servicemen to take their families), there have been so many events held in FL in recent years that the shine has probably worn off for civvy attendees.
The attendance figures for the past 11 years were as follows:
1998 (Anaheim) = 12,300
1999 (Dallas) = 11,700
2000 (Las Vegas) = 13,750
2001 (Anaheim) = 11,700
2002 (Orlando) = 11,824
2003 (Dallas) = 12,877
2004 (Las Vegas) = 15,152
2005 (Anaheim) = 14,000
2006 (Dallas) = 16,628
2007 (Orlando) = 14,806
2008 (Houston) = 17,373
The biggest deciding factor is usually the phase of the market cycle (i.e. upswing or downswing). Given the current recession and the lack of any major new iron on display, I wouldn't expect Heli-Expo '09 to be a record year.
I/C