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 |      6,048       60.48       60.48
       2010 |        649        6.49       66.97
       2011 |      1,315       13.15       80.12
       2012 |      1,088       10.88       91.00
       2013 |        462        4.62       95.62
       9998 |         69        0.69       96.31
       9999 |        369        3.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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