I think you need more data to know if there is a problem, lowered SAT score average may be that more people are attempting the SAT that previously wouldn't, which in and of itself isn't an issue.

If I had to hazard a guess with only the data presented, both stats are likely being influenced by increased pressure to get a high school diploma & college degree, as higher percentages of job requirements list at least the former, but a lot of times list college degree when it may not be needed. So more people try to get into college by taking the SAT.