the Australian and British pounds was set at 0.8 GBP (16 shillings sterling; A£1 5s = £1 sterling). However, those new developments did not entirely supplant the traditional relationship with Britain, and Australia remained a part of the "Sterling Zone" until 1967. That reflected Australia's historical ties as well as a view about the stability in value of the British pound. After a brief period of disruption caused by the Second World War, the United Kingdom returned to its position as Australia's main trading partner. In 1949, the United Kingdom devalued the pound sterling against the US dollar by 30%, and Australia followed suit so that the Australian pound would not become overvalued in sterling zone countries with which Australia did most of its external trade. As the pound sterling went from US$4.03 to US$2.80, the Australian pound went from US$3.224 to US$2.24. Relative to the pound sterling, the Australian pound remained the same at A£1 5s = £1 sterling. With the breakdown of the Bretton Woods system in 1971, Australia converted the traditional peg to a fluctuating rate against the US dollar. In September 1974, Australia valued the dollar against a basket of currencies called the trade weighted index (TWI) in an effort to reduce the fluctuations associated with its tie to the US dollar. The daily TWI valuation was changed in November 1976 to a periodically adjusted valuation. On 12 December 1983, Australia floated the Australian dollar, with the exchange rate reflecting the balance of payments and other market drivers. Immediately after 1945 Australia continued to be governed by the ALP, which adopted a policy of reconstruction based on the principles of "nationalisation and rationalisation". This dictated that the government maintain control over the "commanding heights" of the economy in order to continue economic growth, restrain inflation and institute full employment. A number of Australian companies such as QANTAS were nationalised in this period, while a range of government run enterprises such as TAA and the ANL were set up to expand the government sector. In 1948 the Snowy Mountain River Project was commenced. This policy achieved high economic growth, but led to growing political opposition, especially after the failure of the government to nationalise the banking sector in 1948. Political opponents also capitalized on the retention of rationing of food and petrol. As a result, in 1949 the government was replaced at national elections with a more