Frequencies for psp_use variable in parkwork dataset :

special use |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,134       98.95       98.95
          1 |          3        0.26       99.21
          5 |          7        0.61       99.83
          7 |          1        0.09       99.91
          8 |          1        0.09      100.00
------------+-----------------------------------
      Total |      1,146      100.00

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