The pilot certification numbers for the last 10 years are graphed here for reference:
AOPA Online: General Aviation Trends
Here are the trends for the last 2 full years:
PILOT CERTIFICATION ISSUANCES
2009 / 2010 / % Change / Change
Student 55,786 56,658 2% 872
Private 19,893 14,977 -25% -4,916
Commercial 11,383 8,056 -29% -3,327
ATP 3,113 3,072 -1% -41
CFI 4,348 4,486 3% 138
Instrument 25,337 17,603 -31% -7,734