Frequencies for first 10,000 rows of ekg variable in nhamcsed1999 dataset : ekg | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,547 85.47 85.47 1 | 1,453 14.53 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016