user: Question: Around what time frame release a Sampling Rate of 12-bit 40kHz?
Columns: ['Model', 'Release Date', 'Price', 'MIDI Inputs/Outputs', 'Sampling Rate', 'Sampling Memory/Upgrade-able', 'Sampling Time', 'Storage Method', 'Pad Banks']
Types: ['text', 'real', 'text', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['MPC60', 1988.0, '$5,000', '2 in, 4 out', '12-bit 40kHz', '750 kB / 1.5 MB', '(13.1 sec) / (26.2 sec)', 'Internal 3½" floppy drive', 4.0]
SQL:

assistant: SELECT "Release Date" FROM "Table" WHERE "Sampling Rate" = '12-bit 40kHz';