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

      First |
Accident,et |
     c-Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,402       44.02       44.02
         84 |      1,251       12.51       56.53
         85 |      1,836       18.36       74.89
         86 |      1,364       13.64       88.53
         87 |        509        5.09       93.62
         99 |        638        6.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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