CNNMoney.com || Most lucrative college degrees

Math majors don't always get much respect on college campuses, but fat post-grad wallets should be enough to give them a boost.

The top 15 highest-earning college degrees all have one thing in common -- math skills. That's according to a recent survey from the National Association of Colleges and Employers, which tracks college graduates' job offers.

"Math is at the crux of who gets paid," said Ed Koc, director of research at NACE. "If you have those skills, you are an extremely valuable asset. We don't generate enough people like that in this country."

This year Rochester Institute of Technology hosted recruiters from defense-industry firms like Lockheed Martin and Northrop Grumman, as well as other big companies like Microsoft and Johnson & Johnson.

"The tech fields are what's driving salaries and offers, and the top students are faring quite well," said Emanuel Contomanolis, who runs RIT's career center.

Specifically, engineering diplomas account for 12 of the 15 the top-paying majors. NACE collects its data by surveying 200 college career centers.

Energy is the key. Petroleum engineering was by far highest-paying degree, with an average starting offer of $83,121, thanks to that resource's growing scarcity. Graduates with these degrees generally find work locating oil and gas reservoirs, or in developing ways to bring those resources to the Earth's surface.

"Exploration for new energy sources is high," Koc said. "The oil and gas industry has done relatively well the past year, even though oil prices are off right now."

Other highly-paid engineering majors include chemical engineers, who employ their skills to make everything from plastics to fuel cells and have an average starting offer of $64,902.