[cwilby]

That literally leads to the conclusion that prices rose, in your example.

[rflrob]

The conclusion that “prices rose” is the correct one. What you should not conclude, even though the inflation has been at 20% all year is that “prices are (still) rising”.

[dcow]

But they have risen since last year. YoY they are still rising.

[Dylan16807]

You can't use "rising" to strictly talk about the past. You need to expect it in the future too. If you don't expect the price to be higher a year from now, then it's not "rising YoY", it merely "rose YoY".