Frequencies for ptype variable in parkwork dataset :

  unit type |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        617       56.55       56.55
          3 |        440       40.33       96.88
          4 |         34        3.12      100.00
------------+-----------------------------------
      Total |      1,091      100.00

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