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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,166       21.66       21.66
          1 |        609        6.09       27.75
          2 |      1,084       10.84       38.59
          3 |      1,697       16.97       55.56
          4 |      4,265       42.65       98.21
          5 |         56        0.56       98.77
          9 |        123        1.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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