Frequencies for first 10,000 rows of bladcath variable in nhamcsed2002 dataset : bladder | catheter | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,860 98.60 98.60 1 | 140 1.40 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016