Frequencies for zip variable in hcris2552_96_1995 dataset :

        zip |      Freq.     Percent        Cum.
------------+-----------------------------------
      29550 |          1       50.00       50.00
      36784 |          1       50.00      100.00
------------+-----------------------------------
      Total |          2      100.00

by Jean Roth , jroth@nber.org , 6 Sep 2018