user: ### NOW ANSWER:
Question: what is the number of sites when the number of screens is 687 and rank is more than 7?
Columns: ['Rank', 'Circuit', 'Headquarters', 'Screens', 'Sites']
Types: ['real', 'text', 'text', 'real', 'real']
Sample row: [1.0, 'Regal Entertainment Group', 'Knoxville,TN', 7367.0, 580.0]
SQL:

assistant: SELECT AVG("Sites") FROM "Table" WHERE "Screens" = 687.0 AND "Rank" > 7.0;