Frequencies for first 10,000 rows of cntynat variable in natl1993 dataset :

NCHS County |
         of |
  Occurence |      Freq.     Percent        Cum.
------------+-----------------------------------
      01008 |        350        3.50        3.50
      01028 |        224        2.24        5.74
      01037 |      2,311       23.11       28.85
      01045 |        778        7.78       36.63
      01049 |      1,109       11.09       47.72
      01051 |      1,090       10.90       58.62
      01063 |        303        3.03       61.65
      01999 |      3,835       38.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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