user: Question: What is the Season with an Acquisition via of Rookie Draft, and the number is 15?
Columns: ['Name', 'Position', 'Number', 'School/Club Team', 'Season', 'Acquisition via']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Mark Macapagal', 'Guard', '81, 80', 'San Sebastian', '2007-2011', 'Trade']
SQL:

assistant: SELECT "Season" FROM "Table" WHERE "Acquisition via" = 'Rookie Draft' AND "Number" = '15';