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

 TRAFFICWAY |
       FLOW |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,781       57.81       57.81
          2 |      2,996       29.96       87.77
          3 |      1,082       10.82       98.59
          4 |         91        0.91       99.50
          9 |         50        0.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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