Every year, Forbes magazine publishes a list of the 400 richest people in the US. How the list is compiled is pretty straightforward: it is a list of US citizens (and permanent residents) who have made the substantial majority of their fortunes in the US. It’s a list of billionaires.

Forbes doesn’t explain in detail how they calculate the net worth of the people on the list but we know that they take into account both the assets these people have (companies, cars, boats, planes, islands,...) — and their debts.

Each year, the list is pretty much the same. Same names switching ranks, making a few more or a few less million each year; mostly men, mostly white, mostly above 40.

However, this year brought a new addition to the list: a philanthropy score. For the first time, billionaires are ranked not just on how much money they have but also on their generosity. Each billionaire is scored on a scale of 1 to 5 with 5 being the most generous.