Royston, re. your
"There is every chance it is the beginning of an accelerating trend.
Add in the Africans in the UK carrier pool and new straight infections outnumber gay ones by a factor of up to 5:12

Add them in and it is even further from an exponential progression.
Those figures doubled in the first 2 years, and eight years later have still not doubled again!
Some years they even go down!