Hi,

Prior year - any year before the one you are thinking about

Previous year - the year immediately before the one you are thinking about

So 1812, 1920 and 2001 are all years prior to 2010, whereas 2009 was the previous year.

It would be unusual to use prior year (singlular) though. You might say “In the years prior to 2010, rainfall was much greater” but unlikely to say “in the prior year to 2010…..” as this could mean any single year before 2010. In this context it’s better to avoid the use of prior all together and say something like “In the 10 years before 2010” or simply name the year before 2010.

Hope it helps.

Hello.

Prior means referring to something that existed before the other thing. For example , when we say "prior to this ,I was teaching at a primary school", it means that I am saying, that before this I used to teach at a primary school. So prior basically means "before".

So here, "prior to final%" means before the final.percentage.