Frequencies for first 10,000 rows of cntrspop variable in natl1997 dataset :

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          4        0.04        0.04
          1 |      1,597       15.97       16.01
          2 |      1,020       10.20       26.21
          3 |      2,157       21.57       47.78
          9 |      5,219       52.19       99.97
          Z |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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