How they came up with the figure follows. Gist is that lowest likely figure is 392,979, highest is 900,000+. Mortality rate has more than doubled since the war began. Here it is:
The epidemiological research was carried out on the ground by teams of doctors moving from house to house, questioning families and examining death certificates. Between May and July this year, they visited 1,849 households in 47 separated clusters across the length and breadth of Iraq. The doctors asked about deaths among members of the household in a period before the invasion, from January 2002 to March 2003, and about deaths since. In 92% of cases, they were shown death certificates confirming the cause.
A total of 629 deaths were reported, of which 547 - or 87% - occurred after the invasion. The mortality rate before the war was 5.5 per 1,000, but since the invasion, it has risen to 13.3 per 1,000 per year, they say. Between June 2005 and June 2006, the mortality rate hit a high of 19.8 per 1,000.
Thus they calculate that 654,965 Iraqis have died as a consequence of the invasion. It is an estimate and the mid-point, and most likely of a range of numbers that could also be correct in the context of their statistical analysis. But even the lowest number in the range - 392,979 - is higher that anyone else has suggested. Of the deaths, 31% were ascribed to the US-led forces. Most deaths were from gunshot wounds (56%), with a further 13% from car bomb injuries and 14% the result of other explosions.