Frequencies for first 10,000 rows of popprovm variable in nhamcsed2002 dataset :

estimated # |
 of inscope |
  providers |
     in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
         -1 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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