Frequencies for first 10,000 rows of ekg variable in nhamcsopd2011 dataset :

    EKG/ECG |
(electrocar |
   diogram) |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,856       98.56       98.56
        Yes |        144        1.44      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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