Frequencies for first 10,000 rows of prostrat variable in namcs2002 dataset :

   Provider |
    stratum |
     marker |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,477       14.77       14.77
          2 |        812        8.12       22.89
          3 |        697        6.97       29.86
          4 |      1,023       10.23       40.09
          5 |        504        5.04       45.13
          6 |        478        4.78       49.91
          7 |        480        4.80       54.71
          8 |        506        5.06       59.77
          9 |        665        6.65       66.42
         10 |        640        6.40       72.82
         11 |        479        4.79       77.61
         12 |        503        5.03       82.64
         13 |        546        5.46       88.10
         14 |        551        5.51       93.61
         15 |        639        6.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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