Frequencies for ptype variable in parkwork dataset :

  unit type |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        648       59.50       59.50
          3 |        403       37.01       96.51
          4 |         38        3.49      100.00
------------+-----------------------------------
      Total |      1,089      100.00

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