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

   Rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,022       80.22       80.22
          1 |        722        7.22       87.44
          2 |      1,256       12.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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