Frequencies for first 10,000 rows of cntynat variable in natl1991 dataset :

NCHS County |
         of |
  Occurence |      Freq.     Percent        Cum.
------------+-----------------------------------
      01008 |        425        4.25        4.25
      01028 |        275        2.75        7.00
      01037 |      2,818       28.18       35.18
      01045 |        925        9.25       44.43
      01049 |        224        2.24       46.67
      01051 |      1,079       10.79       57.46
      01063 |        303        3.03       60.49
      01999 |      3,951       39.51      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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