user: Question: Whas is the released date of the memory type DDR2-667?
Columns: ['Model', 'Released', 'Form factor', 'Chipset', 'Memory Type', 'Max. Memory']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Precision M6500', 'Dec 2009', '17"', 'Intel PM55', 'DDR3 1066/1333/1600MHz', '32GB']
SQL:

assistant: SELECT "Released" FROM "Table" WHERE "Memory Type" = 'DDR2-667';