Are my school grades average, above or below?

Hi, I go to a high achieving school so I'm not sure how good my grades are nationally, I'm in the middle of year 9. Thanks for any help and these are the grades I am getting for lessons I am planning to take for gcse: English 7c Maths 7b Biology 6a Chemistry 6b Physics 6b Latin 6b Pe 7b Philosophy 6b Food/nutrition 7a Thanks again :-)