For latest data, try the Iraq Index from the Brookings Institute. It is updated monthly. It also clearly states when the various data was collected.
http://www.brookings.edu/saban/iraq-index.aspx
The Brookings Institute is one of the most respected political think tanks. And no, its not far right; the media usually calls it liberal, although since it provides data that 'supports' Bush, some have accused it of going conservative. It is currently headed by Strobe Talbott, a former Clinton administration appointee.