Frequencies for fldcd_tr variable in vehicle dataset :

 TRUCK FUEL |
       CODE |      Freq.     Percent        Cum.
------------+-----------------------------------
            |         17        2.23        2.23
          * |        534       69.90       72.12
          9 |         98       12.83       84.95
          D |         19        2.49       87.43
          G |         96       12.57      100.00
------------+-----------------------------------
      Total |        764      100.00

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