That’s according to the Economic Policy U.S. Uncertainty Index, as first reported by CNBC. The election of the businessman to the White House was the third biggest creator of economic uncertainty in the U.S. in the index’s 30-year record. Only the fiscal cliff in 2011 and the 9/11 terrorist attacks led to greater levels of worry.

The index, created by economists from Stanford, the University of Chicago, and Northwestern, measures economic policy uncertainty by judging how many times words denoting uncertainty, including Federal Reserve and White House, show up in newspapers. At the same time, the researchers also take into account economic forecasts. The researchers assume that a higher disparity of opinions implies a greater level of uncertainty.

On a global scale, January, the month of Trump’s inauguration, was the most uncertain since the index began tracking international uncertainty a decade age.