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

  HAZARDOUS |
MATERIAL-PL |
      ACARD |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,973       99.73       99.73
          1 |          1        0.01       99.74
          2 |         24        0.24       99.98
          8 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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