Frequencies for first 10,000 rows of popprovm variable in nhamcsed2001 dataset :

estimated # |
 of inscope |
  providers |
     in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        282 |        768        7.68        7.68
        284 |      3,626       36.26       43.94
        317 |      5,283       52.83       96.77
        383 |        323        3.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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