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

    date of |
      first |
     crash, |
 suspension |
         or |
 conviction |
     (year) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,015       60.15       60.15
       2011 |        619        6.19       66.34
       2012 |      1,323       13.23       79.57
       2013 |      1,094       10.94       90.51
       2014 |        493        4.93       95.44
       9998 |         64        0.64       96.08
       9999 |        392        3.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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