Frequencies for first 10,000 rows of cstratm variable in nhamcsed2013 dataset :

  Clustered |
 CSTRATM -- |
     masked |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |      3,053       30.53       30.53
   2.02e+07 |      2,224       22.24       52.77
   2.03e+07 |      1,573       15.73       68.50
   2.04e+07 |      3,150       31.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016