The shift in the time on an AI certainly seems to have been around 2017/18, as that’s when my oncologist recommended I stay with it for a longer period. As his research background is good (up on latest research, cautious about adopting until he sees real evidence) and the research he cited had a significant number involved, I agreed. I doubt if he’d have been impressed by four per cent. But it’s also true that a significant number of women don’t last for five years on AIs and I am not aware of any research on how many have made 10. You do what you reasonably can, on the best advice available and give yourself and your body as much kindness as possible.