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

   Rollover |
       Type |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,221       82.21       82.21
          1 |      1,502       15.02       97.23
          2 |        255        2.55       99.78
          9 |         22        0.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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