Frequencies for first 10,000 rows of citrspop variable in natl1988 dataset :

 Population |
     size - |
   place of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1        0.01        0.01
          2 |        525        5.25        5.26
          3 |      1,433       14.33       19.59
          9 |      8,041       80.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016