THE California HealthCare Foundation has unveiled a brilliant online infographic that powerfully shows how American medical costs have shifted between 1960 and 2010. As the animated treemap changes by year, the role of private insurance and federal programs like Medicare and Medicaid become more prominent, while out-of-pocket expenses shrink.

The use of a treemap was an excellent way to visualise the data. But it was imperfect in at least one respect: it couldn't capture the degree to which costs themselves have increased. To do that, one would need to increase the size of the treemap each year as well. It is easy to appreciate why they designers eschewed this. American healthcare costs increased by roughly 100 times, from $27 billion in 1960 to $2.6 trillion in 2010—the chart would needed to grow 100 times larger. (See stills from the chart below; click on them to go to the animated chart itself.)

Although everything from homes prices to petrol increased a lot over the past half century, America's medical costs grew at an especially hefty rate, from 5% to 18% of GDP. Americans spend about twice as much as Canadians, Germans, French or British. Indeed, the federal government in recent years has begun to spend more on Medicare and Medicaid than on defence.

Among the chart's most arresting stats: the out-of-pocket expenses for prescription drugs was 96% in 1960; today it is a mere 19%—the federal government pays more than half the costs. Likewise, the feds pay for about half the total cost of hospital care, compared with about one-third when Ronald Reagan was elected president in 1980. (And this seemingly "socialised" healthcare spending, it bears noting, predates Obamacare.)

The California HealthCare Foundation is a nonprofit group that aims to improve medical care and lower costs for citizens of the state. The chart is a compliment to its annual report, Health Care Costs 101.