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

   Rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,074       80.74       80.74
          1 |        688        6.88       87.62
          2 |      1,238       12.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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