According to the U.S. Government's Centers for Medicare & Medicaid
Services, health care was about 14.9% of GNP in 2002, the last year
for which there is actual (versus forecasted) data.
To give it some historical perspective, it was 5.1% of GNP in 1960 and
13.4% in 1993. Projections put it at 18.4% by 2013. This web page
gives detailed numbers, including how the money gets spent (hospitals,
"National Health Care Expenditures" (undated)
National Health Expenditure (NHE) historical estimates and projections
are from the National Health Statistics Group in the Office of the
Actuary (OACT), the Centers for Medicare & Medicaid Services (CMS).
Google search strategy:
"health care" percentage of GDP