Frequencies for first 10,000 rows of cntrspop variable in natlterr1997 dataset :

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |      1,058       10.58       10.58
          3 |      2,105       21.05       31.63
          9 |      6,820       68.20       99.83
          Z |         17        0.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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