user: Question: What is the average Fab (nm) of the chipset released in q4 2008 with a RAID larger than 01510?
Columns: ['Model', 'Codename', 'Released', 'Fab ( nm )', 'SATA', 'USB 2.0+1.1', 'USB 3.0', 'Parallel ATA 1', 'RAID', 'Gb Ethernet MAC', 'Package', 'TDP ( W )']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'text', 'text', 'real', 'text', 'text', 'real']
Sample row: ['AMD 480/570/580/690 CrossFire Chipset', 'SB600', '2006', 130.0, '4×3Gbit/s AHCI 1.1 SATA Revision 2.0', '10 + 0', 'No', '1 × ATA/133', 110.0, 'No', '548-pin FC-BGA', 4.0]
SQL:

assistant: SELECT AVG("Fab ( nm )") FROM "Table" WHERE "Released" = 'q4 2008' AND "RAID" > 1510.0;