For comparison, the number of registered climbers for Denali:
2001 1,305
2002 1,232
2003 1,179
2004 1,275
2005 1,340
I would have expected the numbers & trends of registered climbers to track pretty closely between Rainier and Denali. I'm surprised to see the trends be so divergent. I'm sure you've thought about this- what do you suppose is behind the two trends?