There are no data points between 2018 and 2022. Having said that, looking at the more legible charts on page 57 of the full report (same content as the summary chart, just easier to read), it looks like:
Science has been falling pretty steadily starting at the 2009-2012 cycle. No apparent covid effects.
Reading and math both might have had a decline leading up to 2018 (I’d need someone to do actual statistics to know if it is statistically significant). However, they had a significantly bigger decline starting in the 2018-2022 cycle, and continuing into the 2022-2025 cycle.
This drop started in 2018 though?
There are no data points between 2018 and 2022. Having said that, looking at the more legible charts on page 57 of the full report (same content as the summary chart, just easier to read), it looks like:
Ah, NM then.