Commercial carriers' role eroded in 1977.
D006742:Hospital Bed Capacity; D006764:Hospitals, Community / Q000191:economics*; D007341:Insurance / Q000639:trends*; D007343:Insurance Carriers / Q000639:trends*; D007351:Insurance, Liability / Q000639:trends*; D010067:Ownership; D013223:Statistics as Topic; D014481:United States