Changes in sbr

Hello, I have books for SBR exam that are valid until the June 2021 sitting. I will be taking the exam in dec 2021. There will be a new set of books covering period from September 2021 to June 2022. Should I purchase the new set of books or there is not much that changes in the books – in terms of the chapters and questions and therefore buying new books is a waste of money? I did study for March and June exam from the books I currently have however, I was unable to take the exam in those two sittings due to ‘technical difficulties’. Thank you for your help.