Frequencies for first 10,000 rows of ekg variable in nhamcsopd1997 dataset :

        ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,718       97.18       97.18
          1 |        282        2.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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