Frequencies for c_m_zone variable in accident dataset :

CONSTR/MAIN |
     T ZONE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        455       98.27       98.27
          1 |          8        1.73      100.00
------------+-----------------------------------
      Total |        463      100.00

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