Well that’s what it says on the website
It says 55% had first dose so won’t be 64% having boosters
There’s literally no way you believe 64% have had a booster do you?
A percentage figure comes from two numbers - a numerator and a denominator. The numerator is the number, that is a percentage of the other number. 20 out of 100 is 20%, 50 out of 500 is 10%, etc.
Everyone over 50, everyone eligible for a flu vaccine due to underlying conditions, and everyone working in health and social care was offered an autumn booster.
To make things easier, the government present the booster vaccination percentage as the number of people vaccinated, as a percentage of the population aged 50+.
Everyone over the age of 12 was offered the first and second COVID vaccinations, but obviously younger people were less likely to have it, so that percentage figure will be lower, because it includes a lot of people who weren't vaccinated.
So yes, in Sunderland, approximately 64% of everyone in Sunderland over the age of 50, had the autumn booster, because way more than 64% of people who were eligible to have the booster, had the first and second vaccinations.