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

  County of |
 Occurrence |
     (FIPS) |      Freq.     Percent        Cum.
------------+-----------------------------------
      01015 |        425        4.25        4.25
      01055 |        275        2.75        7.00
      01073 |      2,818       28.18       35.18
      01089 |        925        9.25       44.43
      01097 |        224        2.24       46.67
      01101 |      1,079       10.79       57.46
      01125 |        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