What score could I get in TMUA?

So I’m in year 12 and have just completed the 2021 Tmua and scored 23/40 (6.2 for that year). I plan on literally spending the whole summer revising, like literally 2 hours a day for 2 momaths ( I like doing maths). What is a realistic score that I could achieve? baring in mind that the boundary changed this year.