user: Question: What is the Margin, when Date is 19 July 2008 (round 19)?
Columns: ['Margin', 'Score', 'Winning Team', 'Losing Team', 'Venue', 'Date']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [78.0, '78-0', 'Penrith Panthers', 'Gold Coast Titans', 'CUA Stadium', '25 August 2012 (Round 25)']
SQL:

assistant: SELECT "Margin" FROM "Table" WHERE "Date" = '19 July 2008 (round 19)';