Frequencies for first 10,000 rows of popprovm variable in nhamcsopd1996 dataset :

estimated # |
 of inscope |
  providers |
     in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        297 |        712        7.12        7.12
        306 |      3,390       33.90       41.02
        321 |      5,781       57.81       98.83
        368 |        117        1.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016