Frequencies for first 10,000 rows of citrspop variable in natl1976 dataset :

 Population |
     size - |
   place of |
  residence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          3        0.03        0.03
          1 |          3        0.03        0.06
          2 |        778        7.78        7.84
          9 |      9,211       92.11       99.95
          Z |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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