Cigarette smoking in the United States increased rapidly in the 1930s and 1940s. In the 1950s the first reports of the health effects of cigarette smoking appeared and the increases in tobacco consumption were slowed down by a number of reports. Starting in 1973 cigarette consumption per capita decreased steadily. In 1994, it was at the same level as in 1942. Cigarette smoking prevalence reaches a peak between ages 20 and 40 among both males and females and then decreases. Smoking prevalence is higher among males than among females and higher among blacks than among whites. The differences by level of education are the greatest. By 1993 only 25% of Americans over the age of 18 were currently smoking.