Frequencies for cargo_bt variable in vehicle dataset :

 CARGO BODY |
       TYPE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        490       90.07       90.07
         21 |          1        0.18       90.26
         98 |         28        5.15       95.40
         99 |         25        4.60      100.00
------------+-----------------------------------
      Total |        544      100.00

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