Frequencies for first 10,000 rows of injprev variable in nhamcsopd2006 dataset :

     injury |
 prevention |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,617       96.17       96.17
        Yes |        383        3.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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