Not so much that I "want to use those dates", but that I think they are the relevant ones.

The question isn't whether or not Saddam was a murderous bastard, because pretty evidently he was, but whether the net effect of the invasion has been such as to justify it, in terms of the change effected from the situation which was in place in the period preceding the invasion.

From that point of view, assembling those figures, if it could be done, and if someone wants to attempt to do it, or can dig up some existing reliable figures, would be a neutral operation. "Reliable" - there's likely to be the rub...