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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,187       21.87       21.87
          1 |        529        5.29       27.16
          2 |      1,225       12.25       39.41
          3 |      1,709       17.09       56.50
          4 |      4,118       41.18       97.68
          5 |        132        1.32       99.00
          9 |        100        1.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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