user: Question: For sep 18 what is the total number of 1 prize ($)
Columns: ['Date', 'Tournament', 'Location', 'Purse( $ )', 'Winner', 'Score', '1st Prize( $ )']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'real']
Sample row: ['Jan 17', 'MONY Senior Tournament of Champions', 'California', 100000.0, 'Dave Hill (2)', '211 (-5)', 30000.0]
SQL:

assistant: SELECT SUM("1st Prize( $ )") FROM "Table" WHERE "Date" = 'sep 18';