Frequencies for first 10,000 rows of ekg variable in namcs2012 dataset :

    EKG/ECG |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,751       97.51       97.51
        Yes |        249        2.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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