In 2015 the American military, for the first time, used more UAVs to deliver air strikes than manned aircraft in one combat zone. In this case it was Afghanistan, where 56 percent of the air-to-ground weapons used were delivered by UAVs. This is a dramatic shift in Afghanistan because UAVs delivered only five percent of weapons in 2011. In 2015 UAVs used 530 missiles (mostly Hellfires) and bombs (mainly 127 or 227 kg GPS or laser guided ones). . . . This type of aerial attack has, since the 1990s, reduced collateral (unintended) casualties (both military and civilian) to decline over 80 percent compared to previous methods.From here.