user: Question: What type of ship is a Kobben class vessel that has been in service longer than 2?
Columns: ['Vessel', 'Origin', 'Type', 'In service', 'Unit']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Oliver Hazard Perry class', 'United States', 'Frigate', 2.0, 'Anti-Submarine Unit']
SQL:

assistant: SELECT "Type" FROM "Table" WHERE "In service" > 2.0 AND "Vessel" = 'Kobben class';