@Revengeofthepangolins yes it is a relief.
Ds has had a confirmation email from Warwick but nothing yet from Durham but his UCAS email confirming submission was only Friday at 5pm.
Remember that Leeds is his insurance offer of AAA he needs A A A for both Camrbidge and Warwick. He is taking 4 A levels including further maths, has always known he wanted to do CompSci and has done a lot of supercurriculars in that area which he wrote about on his personal statement.
Re contextualising, I am by no means an expert but UCAS provide this info. So when ours sat GCSEs in 2019 schools publish their data in January 2020 which means it is available ahead of applications for September 2021. It looks at how well a student performed against the school's usual results and for the last 10 years at least for historical data.
Plus they use % of free school meals as an indicator of the school's cohort. I know from another thread that some people don't know that FSM = pupil premium meaning the school get money for each child on FSM. They have to publish how this money is spent because it isn't on the lunches but on many things, sometimes enrichment activities ie music lessons and school trips, or it pays for extra staff for behavioural issues etc.
Statistically children on FSM are far less likely to achieve the 5 grades 9-5 including English and maths. In black and white, on average 49.9% of non-disadvantaged pupils achieved the 5 GCSEs grades 9-5 whilst only 24.7% of disadvantaged children did. Considering Pupil Premium has been around a while that gap isn't closing 
They also use POLAR postcode areas for identifying the area you live in which you can look up online. This for us is ridiculous as we live in a nice area but our POLAR covers a large deprived area miles away from us so it benefits us when it really should take smaller areas.