Frequencies for psp_use variable in parkwork dataset :

special use |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,078       98.99       98.99
          3 |          3        0.28       99.27
          5 |          5        0.46       99.72
          7 |          1        0.09       99.82
         13 |          1        0.09       99.91
         99 |          1        0.09      100.00
------------+-----------------------------------
      Total |      1,089      100.00

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