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

  HAZARDOUS |
MATERIAL-PL |
      ACARD |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,985       99.85       99.85
          1 |          1        0.01       99.86
          2 |         10        0.10       99.96
          8 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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