user: Question: What's the release date of the processor with 2.8 GHz of frequency?
Columns: ['Model number', 'sSpec number', 'Cores', 'Frequency', 'Turbo', 'L2 cache', 'L3 cache', 'GPU model', 'GPU frequency', 'Socket', 'I/O bus', 'Release date', 'Part number(s)', 'Release price ( USD )']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power', 'standard power']
SQL:

assistant: SELECT "Release date" FROM "Table" WHERE "Frequency" = '2.8 GHz';