If X says there are 3% with Covid on board you can bet it is much much higher. I would guess 5-10 times higher, with people asymptomatic, people who are not reporting they are sick, and people who are pre-symptomatic.
What is your guess?
Don't count on timing the booster to work. I had two friends who got their second booster (fourth Pfizer shot) and got covid three weeks later. There are always exceptions, espectially with the newer variant of omicron that is 25% more contageous.