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

    VEHICLE |
   TRAILING |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,433       94.33       94.33
          1 |        521        5.21       99.54
          2 |         29        0.29       99.83
          3 |          1        0.01       99.84
          4 |          2        0.02       99.86
          5 |          2        0.02       99.88
          9 |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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