Putting on the Penn State Interfraternity Council/Panhellenic Dance Marathon costs just more than $400,000 a year, according to data released this week by the university.

Logistical and other expenses associated with the 46-hour event, said to be the largest student-run philanthropy in the world, were $408,827 in 2008-2009 fiscal year, the new data show. The figures are included in the university's 2010 Right-to-Know Report, filed under state transparency rules.

With event expenses at that level, about 94.6 percent of donations raised by THON dancers and other volunteers go directly to the Four Diamonds Fund. That's among the most efficient fundraising rates seen in U.S. philanthropic circles, according to the American Institute for Philanthropy.

The institute rates as "most highly efficient" those large charities that commit at least 75 percent of revenues to their respective causes.

"THON owes so much of its success to the thousands of students who volunteer their time to organize, raise funds and contribute their time toward Four Diamonds children," said Penn State spokeswoman Jill Shockey. She said much of THON's efficiency comes from its volunteer-driven structure.

Likewise, THON Overall Chairperson Kirsten Kelly said the "greatest reason we're as efficient as we are is the student volunteers and their hard work throughout the year."

Several committees focus on reducing event costs, Kelly said. The THON Supply Logistics Committee solicits in-kind donations, such as art-and-craft supplies. The Hospitality Committee seeks contributions of food for THON weekend, in February. Other volunteers provide security and clean-up services for the event, held in the Bryce Jordan Center.

"They do so much that we would otherwise have to pay someone to do," Kelly said. She said the low operating expenses also are a reflection on the substantial support THON receives from local businesses.

The THON organization counted a fundraising total of nearly $7.6 million in 2009 and some $7.84 million this year. About 700 student dancers and 15,000 other student volunteers participate in the event, which has generated more than $61 million in its 37-year history.

Proceeds go to the Four Diamonds Fund, which finances pediatric-cancer research and assists the families of pediatric-cancer patients.

Earlier coverage: Read StateCollege.com's 2010 THON event coverage.