Let’s compare it to Afghanistan.
2001: 12
2002: 43
2003: 46
2004: 42
But the situation in Afghanistan is compeletly different, so there could be many reasons for those significantly lower numbers.
Comparing the situation in Iraq now to other countries and times can be done, but you have to be very carefull not to compare apples with oranges. It is for example meaningless to compare the deads among military personal with the deads among civilians in New York. We also have to be aware that those numbers do not include any deaths of Iraqi security forces. So comparing it to the deads of police forces in other countries is also shortsighted.
On the other hand we can assume, that a change of casualties from one month to the next is mostly due to a change of violence level. Eigther initiated by insurgents or by the American army.