Frequencies for first 10,000 rows of cstratm variable in nhamcsopd2003 dataset :

  clustered |
psu stratum |
     marker |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |      2,424       24.24       24.24
   2.01e+07 |        130        1.30       25.54
   2.01e+07 |         61        0.61       26.15
   2.02e+07 |      1,767       17.67       43.82
   2.02e+07 |        138        1.38       45.20
   2.02e+07 |        135        1.35       46.55
   2.03e+07 |        757        7.57       54.12
   2.03e+07 |        126        1.26       55.38
   2.04e+07 |        804        8.04       63.42
   2.04e+07 |        143        1.43       64.85
   2.04e+07 |        287        2.87       67.72
   2.04e+07 |        132        1.32       69.04
   4.01e+07 |        896        8.96       78.00
   4.02e+07 |        495        4.95       82.95
   4.03e+07 |      1,297       12.97       95.92
   4.04e+07 |        408        4.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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