Could we look at average SAT scores by year as a proxy? It's not a great metric because not all students take the SAT but I think there's some correlation.

https://blog.prepscholar.com/average-sat-scores-over-time

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jjk166 5 hours ago | parent [-]

There was a major change to the SAT design right around the start of the period of interest which seems to have caused scores to jump.

	▲	pirate787 5 hours ago \| parent [-]
		The change was in fact designed to make the scores jump. The purpose is compressing the top scores to allow universities to be more subjective and still have high averages