Frequencies for first 10,000 rows of hmo variable in nhamcsed2000 dataset :

       does |
    patient |
  belong to |
    an hmo? |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,176       21.76       21.76
          2 |      4,528       45.28       67.04
          3 |      3,210       32.10       99.14
          4 |         86        0.86      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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