US Average Household Income by Year - 收入不止是工资，还包括你出租房的收入，小业主的收入，

以及 self-incorporated 合同工的收入。如果我们谈私校学费，那么 median income 没有 mean (average) income 来得有意义。以下是 US Average Household Income by Year：

https://www.multpl.com/us-average-income/table/by-year