Frequencies for psp_use variable in parkwork dataset :

special use |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,080       98.99       98.99
          1 |          1        0.09       99.08
          2 |          1        0.09       99.18
          5 |          4        0.37       99.54
          6 |          1        0.09       99.63
          7 |          4        0.37      100.00
------------+-----------------------------------
      Total |      1,091      100.00

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