Frequencies for traf_flo variable in accident dataset :

 Trafficway |
       Flow |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        377       66.02       66.02
          2 |        189       33.10       99.12
          3 |          2        0.35       99.47
          4 |          2        0.35       99.82
          9 |          1        0.18      100.00
------------+-----------------------------------
      Total |        571      100.00

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