THANKS, MOOK:

Deaths fall as Baghdad celebrates (BBC, 1/01/08)

The December death toll was 480, down from almost 900 two months previously and about 2,000 in December 2006. [...]

American military deaths also fell in December, dropping to 21 compared to more than 100 in December 2006.

Other likely factors behind the fall in deaths are the emergence of Sunni tribal groups opposed to al-Qaeda and the truce called by Shia militia leader Moqtada al-Sadr.