Frequencies for first 10,000 rows of injury variable in nhamcsopd2005 dataset :

  is injury |
      visit |
   related? |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,823       88.23       88.23
        yes |      1,177       11.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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