Frequencies for haz_carg variable in vehnit dataset :

  HAZARDOUS |
      CARGO |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,461       98.65       98.65
          1 |          1        0.07       98.72
          3 |          2        0.14       98.85
          9 |         17        1.15      100.00
------------+-----------------------------------
      Total |      1,481      100.00

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