user: Question: When there are 7.5 million viewers what is the archive?
Columns: ['Episode', 'Broadcast date', 'Run time', 'Viewers (in millions)', 'Archive']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['" Episode One "', '30January1971', '24:39', '6.1', 'Manual colourisation']
SQL:

assistant: SELECT "Archive" FROM "Table" WHERE "Viewers (in millions)" = '7.5';