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

       Last |
Accident,et |
     c-Year |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,182       41.82       41.82
         75 |        396        3.96       45.78
         76 |      1,031       10.31       56.09
         77 |      2,146       21.46       77.55
         78 |      1,444       14.44       91.99
         99 |        801        8.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016