2008 $5 Fine Silver Proof Coin, 30 Years of Territory Government, Northern Territory. Australia's Northern Territory was part of New South Wales until 1863, when control was transferred to South Australia. Returned to Commonwealth control in 1911, a decade after Federation, the Northern Territory was granted responsible self government in 1978. This silver proof coin celebrates the 30th anniversary of that event. Mintage 12,500. Certificate of Authenticity is included with this coin numbered 0848.