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

      FIRST |
ACCIDENT-YE |
         AR |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,421       54.21       54.21
       1996 |        805        8.05       62.26
       1997 |      1,535       15.35       77.61
       1998 |      1,266       12.66       90.27
       1999 |        522        5.22       95.49
       9999 |        399        3.99       99.48
          . |         52        0.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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