在这一时间段内，随着平均寿命和生育率的提高，石油输出国的人口开始迅速增加。
Over the same period, the populations of OPEC countries started to mushroom, as both life expectancy and fertility rates rose.
由于因心脏病和癌症造成的死亡率下降了，因此美国人目前的平均寿命达到了历史最高点——77.6岁。
Declines in death rates from most major causes - including heart disease and cancer - have pushed Americans' life expectancy to a record 77.6 years.
韩国较高的平均寿命以及较低的出生率使韩国一步一步走向老龄化。
With higher life expectancy and lower birth rate, South Korea is becoming an aging nation.
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