What percentage of doctors, by state, are actually certified by their respective Boards of Medicine?

I'm trying to find a statistical report that provides this information. For instance, the American Board of Internal Medicine certifies about 24 specialties and lists requirements for certification in those specialties, i.e.:Endocrinology, Diabetes, & Metabolism; Hospice & Palliative Medicine; Pulmonary Disease; Interventional Cardiology, Hematology; etc. Each specialty usually has about one certifying board, but my have two.