Studies of combat activity during the Napoleonic and Civil Wars revealed striking statistics. Given the ability of the men, their proximity to the enemy, and the capacity of their weapons, the number of enemy soldiers hit should have been well over 50 percent, resulting in a killing rate of hundreds per minute. Instead, however, the hit rate was only one o two per minute. And a similar phenomenon occurred during World War I: according to British Lieutenant George Roupell, the only way he could get his men to stop firing into the air was by drawing his sword, walking down the trench, "beating [them] on the backside and ... telling them to fire low". World War II fire rates were also remarkably low: historian and US Army Brigadier General S.L.A. Marshall reported that, during battle, the firing rate was a mere 15 to 20 percent; in other words, out of every hundred men engaged in a firefight, only fifteen to twenty actually used their weapons. And in Vietnam, for every enemy soldiers killed, more than fifty thousand bullets were fired.