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

      TOWED |
   TRAILING |
       UNIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,668       86.68       86.68
          1 |        451        4.51       91.19
          2 |         25        0.25       91.44
          3 |          5        0.05       91.49
          9 |         17        0.17       91.66
          . |        834        8.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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