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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,167       21.67       21.67
          1 |        548        5.48       27.15
          2 |      1,190       11.90       39.05
          3 |      1,697       16.97       56.02
          4 |      4,178       41.78       97.80
          5 |         52        0.52       98.32
          6 |          1        0.01       98.33
          9 |        167        1.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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