Frequencies for first 10,000 rows of hmo variable in namcs1997 dataset :

       does |
    patient |
  belong to |
    an hmo? |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,511       25.11       25.11
          2 |      6,562       65.62       90.73
          3 |        788        7.88       98.61
          4 |        139        1.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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