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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,414       24.14       24.14
          1 |        707        7.07       31.21
          2 |      1,151       11.51       42.72
          3 |      1,254       12.54       55.26
          4 |      4,256       42.56       97.82
          5 |         56        0.56       98.38
          6 |          1        0.01       98.39
          9 |        161        1.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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