Federal debt held by the public is set to hit 77 percent of gross domestic product by the end of this year, the highest level seen since shortly after World War II, according to the Congressional Budget Office’s 2017 long-term budget outlook.

Federal debt held by the public, defined as the amount that the federal government borrows from financial markets, has ballooned over the last decade. In 2007, the year the recession began, debt held by the public represented 35 percent of GDP. Just five years later, federal debt held by the public has doubled to 70 percent and is projected to continue rising.

Debt has not seen a surge this large since the increase in federal spending during World War II, when debt exceeded 70 percent of GDP. The budget office projects that growing budget deficits will cause the debt to increase sharply over the next three decades, hitting 150 percent of GDP by 2047.

Deficits are projected to rise over the next few years because government spending is outpacing tax revenue, causing a substantial imbalance in the federal budget. In 2017, the deficit was 2.9 percent of GDP. This is projected to rise to 9.8 percent in 2047.