GCSE maths

Hello , I’ve recently done my GCSEs and currently waiting on results but the one exam I’m most worried about is maths and I was told that the grades boundaries may go up or down depending on this year’s results and last year results so my question is that if a good majority of people achieve a grade C compared to people achieving a grade A e.g if people that achieved a C was 80 percent compared to the people that achieved a A was 20 percent then would that put the grade boundaries up or down

Hello , I’ve recently done my GCSEs and currently waiting on results but the one exam I’m most worried about is maths and I was told that the grades boundaries may go up or down depending on this year’s results and last year results so my question is that if a good majority of people achieve a grade C compared to people achieving a grade A e.g if people that achieved a C was 80 percent compared to the people that achieved a A was 20 percent then would that put the grade boundaries up or down

A certain percentage of people are given each grade a year
I think grade 9 is the top 2%, grade u the the next 15% etc (idk the exact percentages)
But if on average everyone did very well and recieved High grades the grade boundaries will increase. However the percentage of people receiving each grade remains the same.
If the exam was hard and on average people got lower grades, then the grade boundaries decrease (but again preserving the percentage of people falling in each grade)