Frequencies for first 10,000 rows of stratm variable in namcs1999 dataset :

psu stratum |
     marker |
   (masked) |      Freq.     Percent        Cum.
------------+-----------------------------------
        201 |      1,251       12.51       12.51
        202 |        814        8.14       20.65
        203 |      1,227       12.27       32.92
        204 |      1,630       16.30       49.22
        401 |        879        8.79       58.01
        402 |        983        9.83       67.84
        403 |      2,003       20.03       87.87
        404 |      1,213       12.13      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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