user: Question: How many millions of Blackberry OS smartphones were shipped when 10.4 million Symbian smartphones were shipped?
Columns: ['Quarter', 'Android', 'iOS', 'Symbian', 'BlackBerry OS', 'Linux', 'Windows Phone', 'Other', 'Total']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['2013 Q2', '187.4', '31.2', '0.5', '6.8', '1.8', '8.7', '0.0', '236.4']
SQL:

assistant: SELECT "BlackBerry OS" FROM "Table" WHERE "Symbian" = '10.4';