Frequencies for ptype variable in parkwork dataset :

  unit type |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        644       59.41       59.41
          3 |        402       37.08       96.49
          4 |         38        3.51      100.00
------------+-----------------------------------
      Total |      1,084      100.00

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