Frequencies for first 10,000 rows of popprovm variable in nhamcsopd2001 dataset :

estimated # |
 of inscope |
prov in psu |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        282 |        441        4.41        4.41
        284 |      2,420       24.20       28.61
        317 |      7,139       71.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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