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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,110       21.10       21.10
          1 |        693        6.93       28.03
          2 |      1,232       12.32       40.35
          3 |      1,777       17.77       58.12
          4 |      4,006       40.06       98.18
          5 |         19        0.19       98.37
          6 |          1        0.01       98.38
          9 |        162        1.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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