Frequencies for rollover variable in vehicle dataset :

   rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        670       93.58       93.58
          1 |          6        0.84       94.41
          2 |         40        5.59      100.00
------------+-----------------------------------
      Total |        716      100.00

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