Frequencies for first 10,000 rows of cntyres variable in natlterr1998 dataset :

NCHS County |
         of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
      10000 |          3        0.03        0.03
      31000 |          1        0.01        0.04
      52011 |        535        5.35        5.39
      52013 |        356        3.56        8.95
      52016 |        475        4.75       13.70
      52050 |        235        2.35       16.05
      52058 |        524        5.24       21.29
      52065 |      1,079       10.79       32.08
      52999 |      6,783       67.83       99.91
      53999 |          4        0.04       99.95
      59ZZZ |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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