The compensation of college athletes is the focal point of the Ed O'Bannon vs. NCAA trial, but the question of "how" was addressed in depth Friday, day five.

According to the Associated Press, Daniel Rascher, an economist at the University of San Francisco, said on the stand that he has developed revenue sharing models of college athletes. He said his collegiate model is simple: split revenue from TV contracts with players.

Rascher testified the revenue shares for players under his model could be as high as 55 percent and as low as 10 percent. If that model were ever to be proposed to the NCAA, a whole other court dispute would likely be needed to iron out the details.

It was the fifth day of a trial that was five years in the making. O'Bannon, a former UCLA basketball player, and 19 plaintiffs are seeking an injunction that would force the NCAA to compensate its student athletes for use of their names, images and likenesses (NILs).

Though the trial has not been decided, a popular proposal has been that college players would have their compensation stored in a trust fund that would be awarded to them when they leave school.

"We've seen the NCAA change its rules over decades on how much they should be paying athletes," Rascher said on the stand. "The fanaticism and the demand continue to rise during that time period."

Rascher said 65 of the 69 BCS football programs in the 2012-2013 academic year brought in a net surplus of $1.3 billion, the AP reported. Citing data from the U.S. Education Department, Division I basketball and FBS football programs made about $4.5 billion in that timeframe.

As O'Bannon said in his earlier testimony, the revenue pie is "huge" in college sports, especially with how TV contracts have ballooned to the point where now networks are sprouting up just to air college sports.

"The big thing to understand is how much is being brought in," O'Bannon said on the stand. "When the pie that is brought in is huge, I think it's big enough for everyone to share a piece of that pie."