Fiame Mata'afa Faumuina Mulinu’u II, one of the four highest-ranking paramount chiefs in the country, became Samoa's first Prime Minister. Two other paramount chiefs at the time of independence were appointed joint heads of state for life. Tupua Tamasese Mea'ole died in 1963, leaving Malietoa Tanumafili II sole head of state until his death on 11 May 2007, upon which Samoa changed from a constitutional monarchy to a parliamentary republic de facto. The next Head of State, Tuiatua Tupua Tamasese Efi, was elected by the legislature on 17 June 2007 for a fixed five-year term, and was re-elected unopposed in July 2012.

Answer this question, if possible (if impossible, reply "unanswerable"): For how long of a term was Malietoa Tanumafili II elected in 2007?
unanswerable