That's a very interesting point Tom. Whether something 'sounds' right, is obviously fairly subjective, and language of course is not static, but a living and constantly evolving phenomenon.

I have obviously not come across the word 'prior' used in the way you describe it, which is perhaps why I immediately stumbled over the word when I read it. I would use 'prior' for example when specifically naming ad point in time, such as: In the years prior to 1978 . . . or Prior to this event . . . etc.

However the more often one hears the word used in a specific context, the more 'natural' it sounds. So just because I am not familiar with it in this context, does not mean that it's not correct. 😀

I just think about the thousands of words that Shakespeare apparently introduced into the English language - they must have sounded pretty strange at first. Words are so malleable, the more they are used in a specific context, the more they take on that nuance of meaning.

Wendy, Actually, the expression “in comparison to the prior year/quarter/specified time period…” is very often used in statutory financial reports filed with the regulators. But “prevoius” is good as well.

Tom - I don't think 'prior' works well in this context. I think you have to use the word 'previous' here.
In comparison to / or / Compared to the previous year, (the year immediately preceding this one)