The American Trucking Associations advanced seasonally adjusted For-Hire Truck Tonnage Index fell 6.2% in December, losing ground after a strong showing in November.

The Truck Tonnage Index equaled 133.8 in December, down from 142.7 in the month before. The all-time high reading occurred in February of last year, at 144.

Compared to last December, the index is only down 0.7%. In November the index increased 5.9% year-over-year and for the whole year, tonnage was up 2.5%.

“The ups and downs that plagued most of 2016 continued in December,” said Bob Costello, ATA chief economist. “I don’t recall a year in recent memory with so many large swings on a month-to-month basis.”

The not seasonally adjusted index, which represents the change in tonnage actually hauled by fleets before seasonal adjustment, equaled 133.9, down 1.6% from November.

“Looking ahead, there are some positive signs for truck tonnage. This includes the continued spending by consumers, larger wage gains, and solid home construction,” said Costello. “Factory output will continue to be soft, but it should be better this year than last year. And most importantly, the supply chain continues to make progress reducing bloated inventories, which will help truck volumes going forward.”