From the New York Times:
The chart shows deaths of identified United States service members directly involved in the war in Afghanistan. Rocket-propelled grenades and small-arms fire took the largest number of American lives earlier in the war. In 2008, deaths from improvised explosive devices, or I.E.D.’s, began to make up a larger share of combat deaths.
JULY 20, 2008
Nearly seven years after the start of the war, the death toll reaches 500
MAY 18, 2010
Less than two years later, the war kills another 500, bringing the death toll to 1,000
AUGUST 23, 2012
Death toll reaches 2,003