user: Question: Which Average has a Tally of 2-12, and a Total larger than 18?
Columns: ['Rank', 'Player', 'County', 'Tally', 'Total', 'Matches', 'Average']
Types: ['real', 'text', 'text', 'text', 'real', 'real', 'real']
Sample row: [1.0, "Tony O'Sullivan", 'Cork', '0-31', 31.0, 4.0, 7.75]
SQL:

assistant: SELECT "Average" FROM "Table" WHERE "Tally" = '2-12' AND "Total" > 18.0;