Frequencies for first 10,000 rows of cityres variable in natl1986 dataset :

  NCHS City |
         of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
        008 |        713        7.13        7.13
        021 |        445        4.45       11.58
        023 |        638        6.38       17.96
        024 |        320        3.20       21.16
        033 |          1        0.01       21.17
        086 |          1        0.01       21.18
        999 |      7,880       78.80       99.98
        ZZZ |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016