Frequencies for first 10,000 rows of ekg variable in nhamcsed2005 dataset : ekg/ecg | (electrocar | diogram) | Freq. Percent Cum. ------------+----------------------------------- no | 8,269 82.69 82.69 yes | 1,731 17.31 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016