Frequencies for first 10,000 rows of tobacco variable in nhamcsopd2004 dataset : tobacco | use/exposur | e | Freq. Percent Cum. ------------+----------------------------------- no | 9,628 96.28 96.28 yes | 372 3.72 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016