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

 school bus |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         17        0.17        0.17
          2 |          2        0.02        0.19
          3 |      9,981       99.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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