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

      TOWED |
   TRAILING |
       UNIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,321       93.21       93.21
          1 |        577        5.77       98.98
          2 |         45        0.45       99.43
          4 |          1        0.01       99.44
          5 |          8        0.08       99.52
          9 |         48        0.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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