WELLINGTON, March 1 (Xinhua) -- Record export lamb and butter prices helped boost New Zealand's terms of trade by 0.8 percent in the December 2017 quarter, to another new high, the statistics department Stats NZ said on Thursday.

Export meat prices rose 7.5 percent in the December 2017 quarter, mainly reflecting high lamb prices, which was up 12 percent, Stats NZ said.

The terms of trade is a measure of the purchasing power of New Zealand's exports abroad and an indicator of the state of the overall economy, it said, adding that prior to 2017, the last high for the terms of trade was the June 1973 quarter, influenced by commodity price rises for dairy, meat, and wool in the early 1970s.

In the December 2017 quarter, total export prices rose 4.9 percent, with dairy and forestry prices also contributing to the rise, it said.

"Dairy prices have been generally high in 2017, with butter rising 11 percent in the December 2017 quarter to reach a new peak," business prices manager Sarah Williams said, adding that export prices for butter have nearly doubled since September 2016, up 93 percent.

Total import prices rose 4 percent in the December 2017 quarter, with crude oil leading the rise, statistics show.