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

      FIRST |
ACCIDENT-YE |
         AR |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,324       53.24       53.24
       1998 |        893        8.93       62.17
       1999 |      1,592       15.92       78.09
       2000 |      1,203       12.03       90.12
       2001 |        528        5.28       95.40
       9999 |        408        4.08       99.48
          . |         52        0.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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