It has been held biennially since its first successful event in 2001.
They were held biennially up to 2003 (with the exception of 1977 and 1978).
Town elections are held biennially during odd years in May.
Since 2000, they have been held biennially, in even-numbered years.
It is held biennially, and has been held since 2006.
The event has also been held in Brisbane biennially since 2002.
A sculpture competition is held biennially to provide new additions.
Several pieces are on view from the Museum's most recent outdoor sculpture competition, held biennially.
A national conference is held biennially for members of the state-based societies.
It has been an annual race since 1990 - it was held biennially over the eight years before this date.