Frequencies for first 10,000 rows of cntrspop variable in natl1996 dataset :

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          7        0.07        0.07
          1 |      1,568       15.68       15.75
          2 |      1,002       10.02       25.77
          3 |      2,170       21.70       47.47
          9 |      5,253       52.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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