Frequencies for first 10,000 rows of citrspop variable in natl1990 dataset :

 Population |
     size - |
   place of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |        850        8.50        8.52
          3 |      1,471       14.71       23.23
          9 |      7,675       76.75       99.98
          Z |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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