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

      Towed |
   Trailing |
       Unit |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,931       99.31       99.31
          1 |         69        0.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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