The Federal Reserve raised a key interest rate for only the second time since 2008 Wednesday, and left its economic projections mostly unchanged despite granting the uncertainty of how Donald Trump’s economic policies could alter the economy and its future decision-making.

Chairwoman Janet Yellen announced that the federal funds rate, or the rate banks charge each other for short-term loans, would increase to a range between 0.5 and 0.75 percent, still substantially low by historical standards. She cited expectations that inflation would continue creeping toward a Fed target and the unemployment rate would remain steady below 5 percent.