Frequencies for first 10,000 rows of inj_sev variable in person dataset :

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,062       20.62       20.62
          1 |        665        6.65       27.27
          2 |      1,070       10.70       37.97
          3 |      1,978       19.78       57.75
          4 |      4,008       40.08       97.83
          5 |         59        0.59       98.42
          6 |          1        0.01       98.43
          9 |        157        1.57      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016