Public investment at the lowest level since late 1940s

Austerity is bad, we all know that (well not all). But austerity regarding public investment is even worse, since it reduces potential growth. Below the figure for public investment in the US from Truman to Obama (source here).

The average for the post-war period is around 5% of GDP, but it stands now at 3.6%. This is the lowest level since the end of WW-II led to a collapse of public investment.