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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,041       20.41       20.41
          1 |        510        5.10       25.51
          2 |      1,362       13.62       39.13
          3 |      1,704       17.04       56.17
          4 |      4,197       41.97       98.14
          5 |        103        1.03       99.17
          9 |         83        0.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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