world fertility的意思|示意

However, the fall in fertility is already advanced in most of the world.

然而，世界大部分地区的生育率(繁殖力)已经下降。

But even in the remaining, poorer, half of the world, fertility rates have come down spectacularly, from 5.2 in 1970-75 to 2.6 now.

但就算是在较为贫困的另一半世界，生育率也明显下降，从1970到75年的5.2减少到现在的2.6。

the fertility rate of half the world is now 2.1 or less—the magic number that is consistent with a stable population and is usually called “the replacement rate of fertility”.

世界上一半的地区，生育率仅为2.1%，甚至更低。 这一比率通常被称作“生育替代率”，标志着人口数量的稳定。