For instance, 45 percent of the men who had used illicit drugs while serving in the war reported having used cocaine at least five times since 1972, 14 percent of the veterans who had not used illicit drugs during the war reported the same, and 13 percent of the controls reported the same. But by 1996-97, the use of cocaine reported by all three groups combined was only 9 percent. Similarly, 72 percent of the men who had used illicit drugs while serving in the war reported using marijuana at least five times since 1972, 37 percent of the veterans who had not used illicit drugs during the war reported the same, and 26 percent of the controls reported the same. But by 1996-97, the use of marijuana reported by all three groups combined was only 18 percent.