It is definitely true that tuition has risen faster than inflation, even if state support dropping is accounted for. Good question, though. We know average senior admin salaries have doubled in the past 10 years:
http://uomatters.com/wp-content/uploads/2015/04/Screen-Shot-2015-04-05-at-8.37.40-PM-1024x618.png

and that the number of administrators has also increased, but that is a lot of extra cash so I don't think that would be enough to explain it. PERS exacerbates the problem faster than salary increases, I bet, and health insurance as well.