Frequencies for first 10,000 rows of citrspop variable in natl1986 dataset :

 Population |
     size - |
   place of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |        714        7.14        7.15
          3 |      1,403       14.03       21.18
          9 |      7,880       78.80       99.98
          Z |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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