user: Question: What is the y = 2011 when the y = 2009 is 6 April 2009?
Columns: ['Expression', 'Y = 2008', 'Y = 2009', 'Y = 2010', 'Y = 2011']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['a = Y mod 4', 'a = 0', 'a = 1', 'a = 2', 'a = 3']
SQL:

assistant: SELECT "Y = 2011" FROM "Table" WHERE "Y = 2009" = '6 April 2009';