user: Question: tell the mean of the times competition for the 7 jigs
Columns: ['Rank by average', 'Competition finish', 'Couple', 'Total', 'Number of dances', 'Average']
Types: ['real', 'real', 'text', 'real', 'real', 'text']
Sample row: [1.0, 2.0, 'Darren & Lana', 374.0, 11.0, '34.0']
SQL:

assistant: SELECT AVG("Rank by average") FROM "Table" WHERE "Number of dances" = 7.0;