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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,063       20.63       20.63
          1 |        525        5.25       25.88
          2 |      1,401       14.01       39.89
          3 |      1,638       16.38       56.27
          4 |      4,346       43.46       99.73
          5 |          4        0.04       99.77
          6 |          3        0.03       99.80
          9 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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