Most of the data gathered ended in 2003, the last full year for which statistics were available. That means that most of the deaths caused by the war in Iraq are not included. But by the standards of the bloodiest conflicts since the end of the Second World War, the deaths in Iraq are relatively few. About 27,000 Iraqis and Americans have died.

So, you're citing a piece of research that is based on data collected before the uprising in Fallujah, and before the onset of the current civil war in Iraq and its concommitant attraction of every out of town jihadist from here to Margate? And before the resurgance of Taliban violence in Afghanistan.
It's a bit like picking a similar piece or research based on data collected in February 1914. "Ooh look, Gertrude, it says it's all turning out rosy. That's nice...let's go and by a little gite in Ypres."