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 |      5,926       59.26       59.26
       2009 |        729        7.29       66.55
       2010 |      1,342       13.42       79.97
       2011 |      1,153       11.53       91.50
       2012 |        450        4.50       96.00
       9998 |         61        0.61       96.61
       9999 |        339        3.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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