user: Question: What's the total of Year that's got a Team of Porsche Kremer Racing?
Columns: ['Year', 'Class', 'Team', 'Chassis', 'Tyre', 'Laps']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1992.0, 'C1', 'Mazdaspeed Co. Ltd. Oreca', 'Mazda MXR-01', 'M', 336.0]
SQL:

assistant: SELECT SUM("Year") FROM "Table" WHERE "Team" = 'Porsche Kremer Racing';