Frequencies for first 10,000 rows of prmcarer variable in namcs2009 dataset :

 percent of patient care revenue |
                   from medicare |      Freq.     Percent        Cum.
---------------------------------+-----------------------------------
                           blank |        328        3.28        3.28
less than or equal to 25 percent |      5,156       51.56       54.84
                   26-50 percent |      3,424       34.24       89.08
                   51-75 percent |        902        9.02       98.10
            more than 75 percent |        190        1.90      100.00
---------------------------------+-----------------------------------
                           Total |     10,000      100.00

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