Final answer:
Government spending on Medicare and Medicaid has risen greatly as a share of GDP since 1960, despite overall federal spending remaining within 18% to 22% of GDP.
Step-by-step explanation:
According to the provided information, government spending on healthcare programs, which include both Medicare and Medicaid, has risen greatly as a share of GDP since 1960. While federal spending has ranged from 18% to 22% of GDP during this time, healthcare expenditures have shown a steady increase. This trend reflects the growing costs of providing healthcare services to senior citizens through Medicare and to low-income Americans through Medicaid, the latter of which is also partially funded by state governments.