user: Question: If the place is smaller than 8 and they played more than 18, what is the total number of goals conceded?
Columns: ['Place', 'Team', 'Played', 'Draw', 'Lost', 'Goals Scored', 'Goals Conceded', 'Points']
Types: ['real', 'text', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Alianza F.C.', 18.0, 4.0, 2.0, 42.0, 23.0, 40.0]
SQL:

assistant: SELECT SUM("Goals Conceded") FROM "Table" WHERE "Place" < 8.0 AND "Played" > 18.0;