Frequencies for first 10,000 rows of county variable in usstatesingleagesraceadj dataset :

County FIPS |
       code |      Freq.     Percent        Cum.
------------+-----------------------------------
      01900 |        688        6.88        6.88
      02900 |        688        6.88       13.76
      04900 |        688        6.88       20.64
      05900 |        688        6.88       27.52
      06900 |        688        6.88       34.40
      08900 |        688        6.88       41.28
      09900 |        688        6.88       48.16
      10900 |        688        6.88       55.04
      11900 |        688        6.88       61.92
      12900 |        688        6.88       68.80
      13900 |        688        6.88       75.68
      15900 |        688        6.88       82.56
      16900 |        688        6.88       89.44
      17900 |        688        6.88       96.32
      18900 |        368        3.68      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 2 Jan 2016