Frequencies for first 10,000 rows of cstratm variable in nhamcsed2008 dataset :

  clustered |
  cstratm - |
     masked |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |      1,011       10.11       10.11
   2.02e+07 |      1,033       10.33       20.44
   2.03e+07 |        657        6.57       27.01
   2.04e+07 |      1,428       14.28       41.29
   4.01e+07 |        970        9.70       50.99
   4.02e+07 |        861        8.61       59.60
   4.03e+07 |      3,097       30.97       90.57
   4.04e+07 |        943        9.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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