Frequencies for first 10,000 rows of a_sbus variable in veh_aux dataset :

 School Bus |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         12        0.12        0.12
          2 |          1        0.01        0.13
          3 |      9,987       99.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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