Frequencies for first 10,000 rows of injury variable in nhamcsopd2008 dataset :

  is injury |
      visit |
   related? |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,480       84.80       84.80
        yes |      1,520       15.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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