For the fourth time in barely a year, and in the face of intense student protests, the trustees of the California State University voted to raise that system’s tuition rates.

But this vote was different than the ones that went before.

On November 10, 2010, the trustees approved a mid-year tuition hike of five percent and a 2011-12 increase of ten percent on top of that. This July they increased Fall 2011 tuition an additional 12 percent beyond what they’d already agreed to. Today’s vote increases 2012-13 tuition by another nine percent on top of that.

In all, that comes to an aggregate increase of 41% in just three semesters.

But here’s the interesting part: The November 10 mid-year increase was approved by a vote of 14-2, with the only two dissents coming from the state’s lieutenant governor and the board’s student trustee. The first 2011-12 hike was approved by a 13-3 vote, and the July increase passed by a 13-2 margin.

Today’s vote? Nine to six.

Four trustees flipped from yes to no since the board’s last tuition vote. If just two of the remaining nine had joined them, this hike would have been rejected.