user: Question: What are the least Top-5 finish when the events are greater than 18?
Columns: ['Tournament', 'Wins', 'Top-5', 'Top-10', 'Top-25', 'Events', 'Cuts made']
Types: ['text', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Masters Tournament', 0.0, 1.0, 2.0, 4.0, 4.0, 4.0]
SQL:

assistant: SELECT MIN("Top-5") FROM "Table" WHERE "Events" > 18.0;