Frequencies for first 10,000 rows of ekg variable in nhamcsed2015 dataset :

    EKG/ECG |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,036       80.36       80.36
        Yes |      1,964       19.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017