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

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         49        0.49        0.49
          2 |          4        0.04        0.53
          3 |      4,159       41.59       42.12
          9 |      5,788       57.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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