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

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,001       20.01       20.01
          1 |        721        7.21       27.22
          2 |      1,075       10.75       37.97
          3 |      2,062       20.62       58.59
          4 |      3,951       39.51       98.10
          5 |         54        0.54       98.64
          9 |        136        1.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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