Roughly how much literature in my English Lit personal statement?

I know there is no ‘set’ number of books to have in a personal statement but I am wondering what the general standard is, particularly as I am applying to a couple of competitive Russell groups. I spoke to some people doing these degrees and they seemed to average around 10+ pieces of primary literature - so I’m wondering if it’s okay to only have 7 pieces of primary literature since I also discuss some criticism?
(For reference this is what I have so far):
4 books
3 papers of criticism
3 plays
Thanks!

I think this is plenty! It’s better to discuss fewer pieces of literature in greater depth than to briefly mention something. I did my personal statement for classics but mostly talked about literature. I mentioned:
This took up most of my character count.