Frequencies for first 10,000 rows of cardmon variable in nhamcsed2001 dataset : cardiac | monitor | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,505 95.05 95.05 1 | 495 4.95 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016