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

 percent of patient care revenue |
              from other sources |      Freq.     Percent        Cum.
---------------------------------+-----------------------------------
                           blank |        328        3.28        3.28
less than or equal to 25 percent |      9,546       95.46       98.74
                   26-50 percent |          5        0.05       98.79
                   51-75 percent |         65        0.65       99.44
            more than 75 percent |         56        0.56      100.00
---------------------------------+-----------------------------------
                           Total |     10,000      100.00

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