Frequencies for first 10,000 rows of rcity_pop variable in natl2004 dataset :

 Population |
         of |
  Residence |
   City U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |      4,258       42.58       42.58
          3 |          2        0.02       42.60
          9 |      5,737       57.37       99.97
          Z |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016