Frequencies for first 10,000 rows of ekg variable in nhamcsed2007 dataset : ekg/ecg | (electrocar | diogram) | Freq. Percent Cum. ------------+----------------------------------- no | 8,095 80.95 80.95 yes | 1,905 19.05 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016