Inflation increases 7% over past year, highest in nearly 40 years

The Consumer Price Index over the past 12 months increased 7%, the Labor Department reported Wednesday. 

The index show inflation, what U.S. consumers pay for goods, increased at its fastest 12-month pace in nearly 40 years during December.

The CPI on a monthly basis increased 0.5%, according to the department's Bureau of Labor Statistics.

Economists surveyed by Dow Jones expecting an increase of 7% on an annual basis and 0.4% from November, according to CNBC.