Frequencies for first 10,000 rows of cityres variable in natl2001 dataset :

    City of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
        008 |        749        7.49        7.49
        012 |          1        0.01        7.50
        017 |          1        0.01        7.51
        023 |        317        3.17       10.68
        028 |        557        5.57       16.25
        029 |        505        5.05       21.30
        999 |      7,869       78.69       99.99
        ZZZ |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015