Frequencies for first 10,000 rows of cntynat variable in natl1997 dataset :

NCHS County |
         of |
  Occurence |      Freq.     Percent        Cum.
------------+-----------------------------------
      01008 |        293        2.93        2.93
      01037 |      2,445       24.45       27.38
      01045 |        817        8.17       35.55
      01049 |      1,235       12.35       47.90
      01051 |        989        9.89       57.79
      01052 |        322        3.22       61.01
      01063 |        412        4.12       65.13
      01999 |      3,487       34.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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