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

     injury |
   severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,589       25.89       25.89
          1 |        812        8.12       34.01
          2 |      1,114       11.14       45.15
          3 |      1,085       10.85       56.00
          4 |      4,265       42.65       98.65
          5 |          3        0.03       98.68
          6 |          1        0.01       98.69
          9 |        131        1.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016