It looks like a bimodal distribution of some kind.

它看起来像是某种双分布。

So it's possible you actually have a bimodal distribution.

所有能你实际上有一个双分布。

So it's also possible it could be bimodal.

所它也有能是双。

It was pretty bimodal where we had India, China, Africa were poor and then Europe, U.S., Japan starting to be fairly well-off and not much in the middle.

那时印度、中国及非洲都是十分贫穷。那时欧洲，美国和日本正走向富强之路，位于中间国家并不多。

Myasthenia gravis preferentially affects young women in their 20s and 30s and older men in their 60s and 70s, but the cause of this odd " bimodal" distribution of age-of-onset isn't quite clear.

重症肌无力易影响二三十岁年轻女性和六七十岁老年男性，但这种奇怪“双”发病年龄分布原因尚不清楚。