Where Does Obama Get His Abortion Statistics?

Abortion proponents like to say that the number of abortions went up under George W. Bush. Obama just said so during the Saddleback Faith Forum: (Correction: I heard that wrong the first time…Obama says they haven’t gone down – still wrong – they have – ed.)

This way, abortion proponents can claim to have some moral authority when they say that they would like to see fewer abortions, even though they have a record of supporting abortion, (in Obama’s case an uber-record of supporting abortions).

John Kerry, Howard Dean, and Hillary Clinton used that ploy during the 2004 election cycle, and it was debunked by Fact Check.Org in 2005:

Politicians from Hillary Clinton and John Kerry to Howard Dean have recently contended that abortions have increased since George W. Bush took office in 2001. This claim is false. It’s based on an an opinion piece that used data from only 16 states. A study by the Alan Guttmacher Institute of 43 states found that abortions have actually decreased. Update, May 26: The author of the original claim now concedes that the Guttmacher study is “significantly better” than his own.

The abortion statistics found here show the downward trend continuing through 2007.

So which statistics is he using, I’d like to know?