A record number of companies have received a perfect score on gay workplace issues, according to a new report.

The Human Rights Campaign (HRC), the nation's largest gay rights advocate, released its 2010 survey on GLBT discrimination in corporate America. The report, known as the Corporate Equality Index, is a scorecard of sorts which rates companies on several gay, lesbian, bisexual and transgender workplace policies and assigns each a rating from 0- to 100- percent. This year, corporations achieving a perfect score grew to a new record.

Over half of the 590 corporations rated received a score of 100 percent. These companies employ nearly 9 million full-time workers.

“The Corporate Equality Index 2010 shows that, even in the most challenging economy, leading employers are forging ahead of federal and state law to recruit and retain a diverse workforce — regardless of employees’ sexual orientation and gender identity or expression,” Joe Solmonese, president of HRC, said in a statement. “While Congress considers a federal law that prohibits workplace discrimination based on sexual orientation and gender identity or expression, businesses can take immediate steps to ensure all employees in their workforce are treated fairly today. These 305 businesses, and all employers actively working to improve their rating, set an example for all U.S. employers, including the federal government.”

Companies are increasingly taking the gay index seriously, and crowing about the achievement in press releases.

“Our perfect score directly reflects Fried Frank's ongoing commitment to maintaining an inclusive environment where we respect and build upon the assets and talents of everyone at the Firm,” the law firm Fried, Frank, Harris, Shriver & Jacobson, LLP said in a statement.

“JetBlue has always done things a little different than the other guys, from the embracing culture our crewmembers have created, to the warm welcome we extend to all customers, to the wide range of organizations we support.” said Dave Clark, chief people officer of JetBlue, in his company's release. “We are proud of HRC's recognition and committed to ensuring that JetBlue continues to be one of America's best companies to work at.”

The index also reported huge gains for transgender employees. A large majority (72%) of indexed companies prohibit discrimination based on gender identity or expression. That's up from 66% last year.

While the average rating across the entire index inched up 3% this year to 86%, the average Fortune 500 score remained flat at 83% from last year.