Frequencies for first 10,000 rows of ekg variable in nhamcsed2011 dataset :

    EKG/ECG |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,049       80.49       80.49
        Yes |      1,951       19.51      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016