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

  HAZARDOUS |
MATERIAL-CL |
     ASS NO |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,985       99.85       99.85
          1 |          1        0.01       99.86
          2 |          3        0.03       99.89
          3 |          2        0.02       99.91
          8 |          2        0.02       99.93
          9 |          1        0.01       99.94
         88 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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