user: Question: What is overall rank when viewers are at 6.59 million?
Columns: ['Episode Number', 'Episode', 'Rating', 'Share', 'Rating/Share (18-49)', 'Viewers (millions)', 'Rank (Timeslot)', 'Rank (Overall)']
Types: ['real', 'text', 'text', 'real', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"Pilot"', '4.8', 8.0, '2.3/6', '7.56', 'TBA', '#35']
SQL:

assistant: SELECT "Rank (Overall)" FROM "Table" WHERE "Viewers (millions)" = '6.59';