user: ### NOW ANSWER:
Question: What year was the US Open that had a partnering of Maikel Scheffers?
Columns: ['Year', 'Championship', 'Partnering', 'Opponents in Final', 'Score in Final']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2007.0, 'Wimbledon', 'Robin Ammerlaan', 'Shingo Kunieda Satoshi Saida', '4–6, 7–5, 6–2']
SQL:

assistant: SELECT SUM("Year") FROM "Table" WHERE "Partnering" = 'Maikel Scheffers' AND "Championship" = 'US Open';