Showing everyone under 40 (including children) as a single group comes across as misleading (at least to me)
I'm a bit mystified by it @wintertravel1980.
I presume he's; despite what his twitter feed says; using the most recent NHS weekly file. As that was published on 27th May and goes up to 23rd May jabs. I've not seen a duplicate publication from PHE; although that is not to say such a thing does not exist.
The NHS file provides 5 year breakdowns starting from age 40; and then lumps the 16-39s at the moment as a single group. I expect this Thursday we'll see the 35-39s added as specific band. The NHS file provides the population data for the 16-39 group and for the under 16s. Not sure therefore why he has lumped both together.
And that's before we get onto the population used. The general consensus as per the notes that accompany the NHS weekly file and the presentation on the dashboard is to use the most recent ONS mid year estimate for the England level uptake percentage and the NIMMS estimates for any geography below that.
He however has applied NIMMS population to the national figures. Using NIMMS indeed delivers 18% for that final group; whereas ONS would be 19.7%.
And just taking the 16-39s as the final group - perfectly understandable had he actually done so - would have yielded 27.6% (erroneously) using NIMMs and 32% using the ONS figure. Worth noting that the NIMMS 16-39 estimate is almost 2.8 million higher than the ONS figure (which of course in the 2019 based mid year estimate). The difference between the NIMMS 0-15 figure and that from the ONS is a much more reasonable 285k.
Could of course just be the typical misalignment between a twitterati's ego and intellectual ability