Frequencies for first 10,000 rows of cntrspop variable in natl1995 dataset :

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          3        0.03        0.03
          1 |      1,599       15.99       16.02
          2 |        514        5.14       21.16
          3 |      2,201       22.01       43.17
          9 |      5,682       56.82       99.99
          Z |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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