Frequencies for first 10,000 rows of popprovm variable in nhamcsed1998 dataset :

estimated # |
 of inscope |
  providers |
     in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        281 |      2,373       23.73       23.73
        323 |      2,357       23.57       47.30
        330 |        768        7.68       54.98
        348 |      4,502       45.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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