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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,170       21.70       21.70
          1 |        563        5.63       27.33
          2 |      1,050       10.50       37.83
          3 |      1,890       18.90       56.73
          4 |      4,158       41.58       98.31
          5 |         32        0.32       98.63
          9 |        137        1.37      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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