Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated.

一般来说，分层是按年进行的，因此我们可以确定记录中观察到的变化的日期。

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The overall population growth rate was down 0.57 percent on an annual basis.

人口的整体增长速度平均每年降低了0.57%。

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The budget deficit jumped by almost 30% on an annual basis in the first six months of 2011.

在2011前半年，预算赤字年同比已经上涨到了30%。

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"They must keep paying that fee on an annual basis until they replenish the .

VOA: standard.2009.04.20

Killowen lodge holds a Battle of the Somme commemoration parade in Coleraine on an annual basis.

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The cross-division games will include one protected matchup on an annual basis between Indiana and Purdue.

WSJ: Rutgers announces 2015 Big Ten football schedule

Unemployment averaged less than 5%, and on an annual basis never was higher than 7%.

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