The long-term trend has been downwards.

长期趋势呈下降态势。

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There have been peaks and troughs in the long-term trend of unemployment.

长期以来失业率一直时起时伏。

《牛津词典》

Chinese scientists blame the falling water levels on global warming and say it's a long-term trend.

中国科学家将其归咎为全球变暖导致降水量减少，并称这是一个长期趋势。

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Yet, the long term trend might be for the U.S. and Europe to consume less.

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Math scores on the NAEP long term trend were stagnant during the same period.

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Other than the fact that Brazilian incomes are rising, which is a long term trend, there are some short-term trends as well.

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