Frequencies for first 10,000 rows of first_yr variable in vehicle dataset :

      First |
Accident,et |
     c-Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,677       46.77       46.77
         87 |        997        9.97       56.74
         88 |      1,801       18.01       74.75
         89 |      1,410       14.10       88.85
         90 |        518        5.18       94.03
         99 |        597        5.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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