Frequencies for first 10,000 rows of prmcarer variable in namcs2007 dataset :

 percent of patient care revenue |
                   from medicare |      Freq.     Percent        Cum.
---------------------------------+-----------------------------------
                           blank |        516        5.16        5.16
less than or equal to 25 percent |      5,180       51.80       56.96
                   26-50 percent |      3,044       30.44       87.40
                   51-75 percent |        931        9.31       96.71
            more than 75 percent |        329        3.29      100.00
---------------------------------+-----------------------------------
                           Total |     10,000      100.00

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