Frequencies for first 10,000 rows of electrol variable in nhamcsed2005 dataset :

electrolyte |
          s |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      7,807       78.07       78.07
        yes |      2,193       21.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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