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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,174       21.74       21.74
          1 |        482        4.82       26.56
          2 |      1,410       14.10       40.66
          3 |      1,499       14.99       55.65
          4 |      4,085       40.85       96.50
          5 |        216        2.16       98.66
          9 |        134        1.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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