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

    vehicle |
   trailing |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,398       93.98       93.98
          1 |        540        5.40       99.38
          2 |         33        0.33       99.71
          5 |          2        0.02       99.73
          6 |          3        0.03       99.76
          9 |         24        0.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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