Frequencies for first 10,000 rows of wrk_zone variable in accident dataset :

  work zone |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,815       98.15       98.15
          1 |        112        1.12       99.27
          2 |         19        0.19       99.46
          3 |          3        0.03       99.49
          4 |         51        0.51      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016