But, remember, this is a very rough estimate.

但，记住，这只是一些粗糙的计算估计。

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Now as I say, I made this calculation some years ago It doesn't really matter how inaccurate it's going to be As we'll see it's very rough but it makes the point ? How many people are there?

现在就像我说的，我很多年前做了这个计算,到底它有多不精确其实无所谓,我们会看到,这个计算很粗糙,但却给出了一个说明,有多少人？

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