看了英文原文，發現我的理解不對，英文很清楚

According to the study, the average 55-year-old’s risk of dementia during their lifetime is 42%, but the risk was not the same at every age. The brunt of it occurred after a person’s 85th birthday. Between ages 55 and 75, the average person’s risk of developing dementia was 4%, according to the study. By the time someone turned 85, their risk was about 20%. Risk didn’t reach 42% until a person’s 95th birthday.