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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,141       21.41       21.41
          1 |        683        6.83       28.24
          2 |      1,122       11.22       39.46
          3 |      1,679       16.79       56.25
          4 |      4,210       42.10       98.35
          5 |         14        0.14       98.49
          6 |          1        0.01       98.50
          9 |        150        1.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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