Frequencies for first 10,000 rows of cityres variable in natl1970 dataset :

  NCHS City |
         of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
        012 |          3        0.03        0.03
        021 |      1,010       10.10       10.13
        066 |          1        0.01       10.14
        075 |          2        0.02       10.16
        078 |          1        0.01       10.17
        084 |          1        0.01       10.18
        102 |          1        0.01       10.19
        156 |          1        0.01       10.20
        999 |      8,980       89.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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