Frequencies for first 10,000 rows of haz_cno variable in vehicle dataset :

  HAZARDOUS |
MATERIAL-CL |
     ASS NO |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,975       99.75       99.75
          1 |          1        0.01       99.76
          2 |          4        0.04       99.80
          3 |         15        0.15       99.95
          8 |          2        0.02       99.97
          9 |          1        0.01       99.98
         88 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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