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

    Date of |
      First |
     crash, |
 suspension |
         or |
 conviction |
     (Year) |      Freq.     Percent        Cum.
------------+-----------------------------------
         -1 |         15        0.15        0.15
          0 |      5,586       55.86       56.01
       2007 |        762        7.62       63.63
       2008 |      1,516       15.16       78.79
       2009 |      1,236       12.36       91.15
       2010 |        451        4.51       95.66
       9999 |        387        3.87       99.53
          . |         47        0.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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