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

      FIRST |
ACCIDENT-YE |
         AR |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,496       54.96       54.96
       2006 |        839        8.39       63.35
       2007 |      1,526       15.26       78.61
       2008 |      1,212       12.12       90.73
       2009 |        475        4.75       95.48
       9999 |        411        4.11       99.59
          . |         41        0.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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