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

     injury |
 prevention |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,586       95.86       95.86
        yes |        414        4.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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