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

   rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,863       78.63       78.63
          1 |        721        7.21       85.84
          2 |      1,416       14.16      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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