Frequencies for first 10,000 rows of ekg variable in nhamcsopd2007 dataset :

    ekg/ecg |
(electrocar |
   diogram) |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,764       97.64       97.64
        yes |        236        2.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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