Again, I don't want to make too much of my estimates because different people would estimate these things in different ways, but that's the theory.

再说一次，我不想太过强调我的估算,因为不同的人,会用不同的方法估算这些数据，但这只是个理论。

耶鲁公开课 - 金融市场课程节选

So, they started to do collecting of data on mortality and they developed something called actuarial science, which is estimating the probability of people living.

他们开始收集死亡率的数据,并且发展出精算学,用来估算人在各年龄段死亡的概率

耶鲁公开课 - 金融市场课程节选