Frequencies for first 10,000 rows of popprovm variable in nhamcsopd1995 dataset :

estimated # |
 of inscope |
  providers |
     in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        306 |      4,293       42.93       42.93
        343 |      5,542       55.42       98.35
        360 |        165        1.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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