A big part of many case if future damages. How much will future treatment cost? How much will be lost in future earnings? How many days of pain will the injured person have to endure?
There’s no certainty in life. But there is the life expectancy table and it’s a big part of what a jury uses to determine how long someone will live (or would have lived).
The life expectancy table is pretty interesting. It puts a lot of things into perspective and in personal injury cases provides a way to add some certainty (or at least evidence based objectivity) when calculating future damages.