Frequencies for first 10,000 rows of cntrspop variable in natlterr1999 dataset :

 Population |
    Size of |
  County of |
  Residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |      1,070       10.70       10.70
          3 |      2,128       21.28       31.98
          9 |      6,791       67.91       99.89
          Z |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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