Frequencies for first 10,000 rows of cntocpop variable in natl1992 dataset :

 Population |
    Size of |
  County of |
 Occurrence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,530       25.30       25.30
          2 |      1,376       13.76       39.06
          3 |      2,754       27.54       66.60
          9 |      3,340       33.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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