Frequencies for first 10,000 rows of zipcode variable in planxw2015 dataset :

  Zip Codes |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 9 Dec 2017