Frequencies for first 10,000 rows of injprev variable in namcs2007 dataset :

     injury |
 prevention |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,579       95.79       95.79
        yes |        421        4.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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