Frequencies for first 10,000 rows of exercise variable in nhamcsopd1994 dataset : exercise | couns/educ | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,460 94.60 94.60 1 | 540 5.40 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016