Over ten percent of the world's population now lives in a jurisdiction where gay and lesbian couples can marry.

Melbourne, Australia-based LGBT rights activist Tony Pitman, spokesman for the group Melbourne Ports Residents for Marriage Equality, made the announcement on Wednesday.

Pitman's first analysis, conducted in July 2013, found there were 607 million people living in states or countries with marriage equality, or 8.6 % of the world's population.

A year later that figure has risen to 725 million, or 10.1% of the world's population.

“Although probably nobody realized it at the time, the key moment came on 20th May this year when the US state of Pennsylvania achieved marriage equality,” Pitman said in a statement.

Pennsylvania became the 19th U.S. state, in addition to the District of Columbia, to allow gay couples to marry when Republican Governor Tom Corbett decided against appealing a federal ruling striking down the state's restrictive marriage ban.

“Pennsylvania with its 13 million people pushed the world figure up over 10% for the first time in history,” Pitman said.

Pitman added that he hopes Australia will soon be added to the list.