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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,296       22.96       22.96
          1 |        606        6.06       29.02
          2 |      1,172       11.72       40.74
          3 |      1,549       15.49       56.23
          4 |      4,207       42.07       98.30
          5 |         52        0.52       98.82
          6 |          1        0.01       98.83
          9 |        117        1.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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