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

  is injury |
      visit |
   related? |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,309       83.09       83.09
        yes |      1,691       16.91      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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