Frequencies for first_yr variable in vehnit dataset :

      FIRST |
ACCIDENT-YE |
         AR |      Freq.     Percent        Cum.
------------+-----------------------------------
       9999 |      1,328      100.00      100.00
------------+-----------------------------------
      Total |      1,328      100.00

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