Frequencies for first 10,000 rows of cntocpop variable in natl1999 dataset :

 Population |
    Size of |
  County of |
 Occurrence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,282       22.82       22.82
          2 |      1,177       11.77       34.59
          3 |      3,046       30.46       65.05
          9 |      3,495       34.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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