user: Question: When did Prime Minister Agathe Uwilingiyimana's mandate end?
Columns: ['Name a', 'Country', 'Office', 'Mandate start', 'Mandate end', 'Term length']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Sirimavo Bandaranaike', 'Ceylon', 'Prime Minister', '21 July 1960', '27 March 1965', '4years, 249days']
SQL:

assistant: SELECT "Mandate end" FROM "Table" WHERE "Office" = 'Prime Minister' AND "Name a" = 'Agathe Uwilingiyimana';