Frequencies for first 10,000 rows of ekg variable in nhamcsopd1998 dataset :

        ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,773       97.73       97.73
          1 |        227        2.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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