Frequencies for first 10,000 rows of cntocpop variable in natl1989 dataset :

 Population |
    Size of |
  County of |
 Occurrence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,549       25.49       25.49
          2 |        690        6.90       32.39
          3 |      2,608       26.08       58.47
          9 |      4,153       41.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016