Frequencies for first 10,000 rows of cntocpop variable in natl1994 dataset :

 Population |
    Size of |
  County of |
 Occurrence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,319       23.19       23.19
          2 |      1,009       10.09       33.28
          3 |      2,864       28.64       61.92
          9 |      3,808       38.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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