What are the OCR GCSE Art and Design Grade Boundaries for the exam and prep (aka "Set Task)?

I thought that the exam and prep was marked out of 100, and an A* would be 95+, but my friend has recently said that 90+ is an A*. I got 91 on my mock and received an A. I did my real GCSE Art earlier this year and was completely happy with the amount of work I did, as I did twice as much prep than what I did for my mock. There has been dispute this year over the marks my school has awarded and apparently there has been overmarking (of an average) of 6 marks, so I'm just wondering where I would sit, as I think everyone exam and prep will get knocked down by 6 marks. I only know this because another art teacher was telling my friend and I happened to be with her, my art teacher (nor this other teacher) has mentioned it to my class or any other classes. Any help re. grade boundaries or past experiences would be greatlych appreciated, thank you :)