Frequencies for first 10,000 rows of citrspop variable in natl1994 dataset :

 Population |
     size - |
   place of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |        723        7.23        7.24
          3 |      1,551       15.51       22.75
          9 |      7,723       77.23       99.98
          Z |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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