Click here to write a Letter to the Editor. U.S. consumer prices rose 0.5% in December, the most since April, following no change in November, the Labor Department said Thursday.The so-called “core” consumer price index excluding food and energy rose 0.2%, also following no change in November, Labor said.Labor also reported that consumer prices rose 2.5% in 2006, the best showing since prices increased by just 1.9% in 2003.Economists had expected the CPI to rise 0.4% for the month, Bloomberg reported.The CPI is the government's broadest gauge of costs for goods and services. Almost 60% of the CPI covers prices consumers pay for services.If consumer prices are climbing, it could reflect an increase in demand for consumer goods, which increases the demand for trucking services.