Frequencies for first 10,000 rows of ocntyfips variable in natlterr2003 dataset :

 Occurrence |
FIPS County |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
         21 |      1,247       12.47       12.47
         25 |        722        7.22       19.69
         31 |        227        2.27       21.96
         97 |        650        6.50       28.46
        113 |      1,147       11.47       39.93
        127 |      2,833       28.33       68.26
        999 |      3,174       31.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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