Frequencies for first 10,000 rows of rcnty_pop variable in linkpe2009psden dataset :

 Population |
         of |
  Residence |
 County U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |        666        6.66        6.66
          9 |      9,323       93.23       99.89
          Z |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015