user: Question: What is the party of the prime minister who left office on 11 March 1983?
Columns: ['Rank:', 'Prime Minister:', 'Party:', 'Assumed Office:', 'Left Office:', 'TOTAL Time in Office:']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Sir Robert Menzies (1894–1978)', 'United Australia', '26 April 1939', '29 August 1941', '18 years, 160 days']
SQL:

assistant: SELECT "Party:" FROM "Table" WHERE "Left Office:" = '11 March 1983';