Frequencies for typeofextracoverageoffered variable in pdp2007 dataset :

       Type of Extra Coverage |
           Offered in the Gap |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
                              |      2,013       71.11       71.11
          All Formulary Drugs |         38        1.34       72.45
                     Generics |        778       27.48       99.93
Generics and Preferred Brands |          2        0.07      100.00
------------------------------+-----------------------------------
                        Total |      2,831      100.00

by Jean Roth , jroth@nber.org , 14 Apr 2016