control over the area known as the Parliamentary Triangle through the National Capital Authority. Residents of the territory elect three members of the House of Representatives and two senators. With 453,324 residents, the Australian Capital Territory is the second smallest mainland state or territory by population. At the , the median weekly income for people in the territory aged over 15 was $998, significantly higher than the national average of $662. The average level of degree qualification in the ACT is also higher than the national average. Within the ACT, 37.1% of the population hold a bachelor's degree level or above education compared to the national figure of 20%. In September 2022, it was announced the border between NSW and the ACT would change for the first time since it was created in 1911. ACT chief minister Andrew Barr said NSW premier Dominic Perrottet had agreed to a proposed border change of in the Ginninderra watershed. History Indigenous inhabitants Aboriginal Australian peoples have long inhabited the area. Evidence indicates habitation dating back at least 25,000 years, and it is possible that the area was inhabited for considerably longer, with evidence of an Aboriginal presence at Lake Mungo dating back around 40,000–62,000 years. The principal group occupying the region were the Ngunnawal people, with the Ngarigo and Walgalu living immediately to the south, the Wandadian to the east, the Gandangara to the north and the Wiradjuri to the north-west. European colonisation Following European settlement, the growth of the new colony of New South Wales led to an increasing demand for arable land. Governor Lachlan Macquarie supported expeditions to open up new lands to the south of Sydney. The 1820s saw further exploration in the Canberra area associated with the construction of a road from Sydney to the Goulburn plains. While working on the project, Charles Throsby learned of a nearby lake and river from the local Indigenous peoples and he accordingly sent Wild to lead a small party to investigate the site. The search was unsuccessful, but they did discover the Yass River and it is surmised that they would have set foot on part of the future territory. A second expedition was mounted shortly thereafter and they became the first Europeans to camp at the Molonglo (Ngambri) and Queanbeyan (Jullergung) Rivers. However, they failed to find the Murrumbidgee River. The issue of the Murrumbidgee was solved in 1821 when Throsby