user: Question: What is the duration when Lok Sabha shows Fifth?
Columns: ['Lok Sabha', 'Duration', 'Name of M.P.', 'Party Affiliation', 'Election Year']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Fourth', '1967-71', 'P. Sivasankaran', 'Dravida Munnetra Kazhagam', 1967.0]
SQL:

assistant: SELECT "Duration" FROM "Table" WHERE "Lok Sabha" = 'Fifth';