Frequencies for last_yr variable in vehnit dataset :

       LAST |
ACCIDENT-YE |
         AR |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          3        0.20        0.20
       2002 |          2        0.14        0.34
       2003 |          1        0.07        0.41
       2004 |          1        0.07        0.47
       2005 |          2        0.14        0.61
       9999 |      1,472       99.39      100.00
------------+-----------------------------------
      Total |      1,481      100.00

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