qnli question: How many years did the Liberals stay in office after the 1949 election? sentence: Australia experienced prolonged economic growth during the post-war boom period of the Menzies Government (1949–1966) and Menzies fulfilled his promises at the 1949 election to end rationing of butter, tea and petrol and provided a five-shilling endowment for first-born children, as well as for others.