Frequencies for first 10,000 rows of ekg variable in namcs2001 dataset : ekg | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,712 97.12 97.12 1 | 288 2.88 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016