"The figures, compiled from Iraqi and international media reports, found US and coalition military forces were responsible for 37% of the deaths, with anti-occupation forces and insurgents responsible for 9%. A further 36% were blamed on criminal violence. "

Media reports aren't a good source. Anyhow, it saying that around 2237 civilians deaths have been caused by "anti-occupation forces and insurgents".

And says "Figures obtained last week from the Iraqi interior ministry put the average civilian and police officer death toll in insurgent attacks from August 2004 to March 2005 at 800 a month. "

So seven months times 800 a month gives 5600 deaths. So these are 5600 deaths which are unrelated to Coalition forces direct involvement.
Also police officers are civilian rather than miltary forces, so the "anti-occupation forces and insurgents" are obviously killing civilians, mostly a small percentage being miltary forces and the Coalition and Iraq security forces are mostly killing terrorists.

What we know is that Coalition forces are not targetting civilians. And we know that the terrorists do not have any uniform that allows a dead terrorist to be identified as non-civilians.
What is known is that terrorist do target civilians and have fact proclaimed Iraqi civilians as targets by the "anti-occupation forces".
And we know that the Coalition forces have been successful at killing far more terrorists than accidentally killing innocent Iraqis caught in the crossfire.
So the killing goes on and it's cause is due to "anti-occupation forces and insurgents" deliberate actions. Also the "36% were blamed on criminal violence" is difficult to tell apart of the terrorists action- after all everything the terrorist do is actually criminal violence.

So at this point it would more accurate to say around 25,000 people have died in Iraq from combat related deaths and this number does not include Coalition forces- and I suppose Saddam's regular Iraqi army forces deaths or other enemy combatants who wears some kind of uniform. It's also know that around 2000 Iraqi miltary forces have been killed fighting the terrorists. And recently there has been reports of factions of the terorists have killing each other.
And it could be possible that large number of this deaths involve actions taken by the terrorists or the deaths of terrorists [and mostly terrorists doing the dying]