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

       does |
    patient |
  belong to |
    an hmo? |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,708       27.08       27.08
          2 |      6,106       61.06       88.14
          3 |      1,012       10.12       98.26
          4 |        174        1.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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