Frequencies for first 10,000 rows of cntocpop variable in natl2002 dataset :

 Population |
    Size of |
  County of |
 Occurrence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         74        0.74        0.74
          2 |          5        0.05        0.79
          3 |      5,392       53.92       54.71
          9 |      4,529       45.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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