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

      TOWED |
   TRAILING |
       UNIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,746       87.46       87.46
          1 |        456        4.56       92.02
          2 |         29        0.29       92.31
          9 |        120        1.20       93.51
          . |        649        6.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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