Usage of より in 今まででいちばん多かった前の年より１５人少なくなりましたが

Question

from this article: https://nhkeasier.com/story/4248/

As I understand it, より has the following usage:

Nより　= rather than/compared to N

so that in this sentence it would be something along the lines of:
"Compared to last year, which up until now had the highest, it (this year) decreased by 15 people."
But from the context of the article, I don't think this is right, as this year should have the highest number of people.

Would appreciate if someone can explain where I am going wrong with my understanding of this grammar.

Answer 1

Your understanding of より is fine; it just means "than ～" here. But you have misunderstood 今まででいちばん多かった前の年. This says 2019 is the worst year in the previous statistics, and the past tense is used simply because the statistics was made in the past. However it does not imply this record has been already broken. That is, as of today, 2019 is still the worst year, and 2020 is the second worst year.

_{(English past tense ("was X") tends to imply it is no longer X now, but Japanese past tense tends not to have this implication.)}