Frequencies for first 10,000 rows of injury variable in natl1998 dataset :

     Injury |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         10        0.10        0.10
          2 |      9,987       99.87       99.97
          9 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015