The facts support a study concerning life expectancy among smokers. Stopping smoking lengthens life expectancy, according to statistics collected by the Cancer Prevention Study II by the American Cancer Prevention Organization to investigate relative risks of smoking. They studied data factoring length of time smoking and age of smoking cessation. The sample was of 1.2 million people (676,306 women and 508,351 men). After removing those not statistically acceptable to the study, 877,243 subjects remained. Data was compiled between 1982 and 1996. Population statistics were supported by the United States Census data from 1990. In addition, statistics were compiled from the National Cause of Death Registry between the years 1989 to 1996.