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

   rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,031       80.31       80.31
          1 |        742        7.42       87.73
          2 |      1,227       12.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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