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

    vehicle |
   trailing |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,396       93.96       93.96
          1 |        531        5.31       99.27
          2 |         42        0.42       99.69
          3 |          1        0.01       99.70
          4 |          4        0.04       99.74
          5 |          2        0.02       99.76
          6 |          6        0.06       99.82
          9 |         18        0.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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