Frequencies for first 10,000 rows of stratm variable in namcs2001 dataset :

psu stratum |
     marker |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        201 |      1,856       18.56       18.56
        202 |        932        9.32       27.88
        203 |        908        9.08       36.96
        204 |      1,189       11.89       48.85
        401 |      1,016       10.16       59.01
        402 |      1,552       15.52       74.53
        403 |      2,043       20.43       94.96
        404 |        504        5.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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