Frequencies for first 10,000 rows of rcnty_pop variable in natl2003 dataset :

 Population |
         of |
  Residence |
 County U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1        0.01        0.01
          1 |          3        0.03        0.04
          2 |      4,265       42.65       42.69
          3 |          9        0.09       42.78
          9 |      5,722       57.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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