Shows pretty clearly how bad the government inflation statistics are.
https://nces.ed.gov/programs/digest/d09 ... 09_078.asp
Estimated average annual salary of teachers in public elementary and secondary schools: Selected years, 1959-60 through 2008-09
Average public school teachers' salary
School year Current dollars constant 2007-08 dollars2
1969-70 8,626 48,343
2008-09 53,910 53,168
Salaries haven't gone up much, according to their inflation metrics. Also, the costs of equipment, benefits, security, food, have all skyrocketed, with our much-higher standards for schools today. They barely served food, and most didn't bother with air conditioning in the 70s.
There's plenty of ways to twist this around, but I'd chalk it up to massive inefficiencies in the system, and a lot of government beaurocracy. Also, the chart format is incredibly misleading, unless you were expecting Reading scores to somehow rise by 200% and keep track with the other metrics on there.