This FACT indicates the percentage of the population in a de facto marriage in each city. A de facto relationship is considered a relationship in which two people who are not married or in a registered relationship live together as a couple. In Australia, there is no minimum time period before one is considered a part of a de facto relationship. In Australia, 10.4 percent of persons over the age of 15 are in such a relationship. According to the 2016 ABS Census, the city with the highest percentage of de facto relationships is Darwin, at 17.1 percent. The city with the lowest is Sydney with at 8.6 percent.