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

CONSTR/MAIN |
     T ZONE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,797       97.97       97.97
          1 |        165        1.65       99.62
          2 |         14        0.14       99.76
          3 |          6        0.06       99.82
          4 |         18        0.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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