Frequencies for mvisobsc variable in vision dataset :

   Driver’s |
     Vision |
Obscured By |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        436       97.10       97.10
          1 |          6        1.34       98.44
         95 |          2        0.45       98.89
         97 |          2        0.45       99.33
         98 |          3        0.67      100.00
------------+-----------------------------------
      Total |        449      100.00

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