Frequencies for tow_veh variable in person dataset :

      Towed |
   Trailing |
       Unit |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,063       80.41       80.41
          1 |          3        0.23       80.64
          . |        256       19.36      100.00
------------+-----------------------------------
      Total |      1,322      100.00

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