Frequencies for first 10,000 rows of bladcath variable in nhamcsed1999 dataset : bladder | catheter | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,830 98.30 98.30 1 | 170 1.70 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016