Frequencies for d_vision3 variable in vehnit dataset :

 DRI VISION |
OBSCURED BY |
          3 |      Freq.     Percent        Cum.
------------+-----------------------------------
         99 |      1,116      100.00      100.00
------------+-----------------------------------
      Total |      1,116      100.00

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