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

      TOWED |
   TRAILING |
       UNIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,317       93.17       93.17
          1 |        542        5.42       98.59
          2 |         51        0.51       99.10
          4 |          1        0.01       99.11
          5 |          1        0.01       99.12
          9 |         88        0.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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