Frequencies for first 10,000 rows of cstratm variable in namcs2012 dataset :

     Masked |
   sampling |
    stratum |
 from which |
   provider |
        was |
   selected |      Freq.     Percent        Cum.
------------+-----------------------------------
   1.01e+07 |        960        9.60        9.60
   1.01e+07 |      1,253       12.53       22.13
   1.02e+07 |      1,230       12.30       34.43
   1.02e+07 |      1,293       12.93       47.36
   1.03e+07 |        666        6.66       54.02
   1.03e+07 |        877        8.77       62.79
   1.04e+07 |        803        8.03       70.82
   1.04e+07 |        900        9.00       79.82
   1.05e+07 |        821        8.21       88.03
   1.05e+07 |      1,059       10.59       98.62
   1.06e+07 |         36        0.36       98.98
   1.10e+07 |         11        0.11       99.09
   1.15e+07 |         21        0.21       99.30
   1.15e+07 |         19        0.19       99.49
   1.20e+07 |         13        0.13       99.62
   1.30e+07 |         38        0.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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