That's not correct. Taking the numbers at face value: out of 100 8th graders, previously 34 were proficient in math. Now 26 are. 23.5% fewer 8th graders are proficient in math. Saying it's an 8% lower number is wrong: the number of 8th graders proficient in math is 23.5% lower. The absolute percentage went down by 8, but who cares?
To illustrate this, consider if 1% of all children were dying of Smallpox, and after the vaccine it dropped to 0%. Did we reduce Smallpox deaths by 1%? No! We eliminated Smallpox deaths; reduced by 100%.
The irony of your statement is left as an exercise for the reader.
