Frequencies for first 10,000 rows of sch_bus variable in accident dataset :

  SCHOOLBUS |
    RELATED |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,975       99.75       99.75
          1 |         25        0.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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