Same-sex marriage could be just the boost the industry needs.

Official figures released on Tuesday show Australians marrying less than at any time since Federation.

Only 4.9 marriages per 1000 Australians were registered in 2016, down from 5.8 in the 1990s, 8.0 in the 1970s and 7.0 at the turn of the 1990s.

And the Australian Bureau of Statistics believes 4.9 might be an overestimate of the marriage rate. "A larger than usual number of 2015 marriage registrations have been delayed until 2016," it reported, meaning that the total included an unusual number of marriages that took place the previous year.