user: Question: What is the winning span of the name Martin Kaymer?
Columns: ['Rank', 'Name', 'Lifespan', 'Country', 'Wins', 'Majors', 'Winning span', 'Span (years)']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'text', 'real']
Sample row: ['1', 'Seve Ballesteros', '1957–2011', 'Spain', 50.0, 5.0, '1976–1995', 20.0]
SQL:

assistant: SELECT "Winning span" FROM "Table" WHERE "Name" = 'Martin Kaymer';