Frequencies for first 10,000 rows of cstratm variable in nhamcsed2003 dataset :

  clustered |
psu stratum |
     marker |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |      1,269       12.69       12.69
   2.01e+07 |        114        1.14       13.83
   2.02e+07 |      1,275       12.75       26.58
   2.02e+07 |         95        0.95       27.53
   2.02e+07 |        186        1.86       29.39
   2.03e+07 |        605        6.05       35.44
   2.03e+07 |         94        0.94       36.38
   2.03e+07 |        215        2.15       38.53
   2.04e+07 |      1,108       11.08       49.61
   2.04e+07 |         78        0.78       50.39
   2.04e+07 |        305        3.05       53.44
   4.01e+07 |        619        6.19       59.63
   4.02e+07 |        940        9.40       69.03
   4.03e+07 |      2,377       23.77       92.80
   4.04e+07 |        720        7.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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