Frequencies for pbswalk variable in pbtype dataset :

   sidewalk |
   presence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,900       62.37       62.37
          1 |      2,085       33.34       95.71
          9 |        268        4.29      100.00
------------+-----------------------------------
      Total |      6,253      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016