Frequencies for first 10,000 rows of cstratm variable in nhamcsopd2005 dataset :

  clustered |
 cstratm -- |
     masked |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |      2,194       21.94       21.94
   2.02e+07 |      1,516       15.16       37.10
   2.03e+07 |        325        3.25       40.35
   2.04e+07 |        362        3.62       43.97
   4.01e+07 |      1,563       15.63       59.60
   4.02e+07 |      1,317       13.17       72.77
   4.03e+07 |      1,378       13.78       86.55
   4.04e+07 |      1,345       13.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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