user: Question: What is their withdrawal rate for the school district with headquarters located in Truro?
Columns: ['School District', 'Headquarters', 'Sector', 'Enrollment (2011-12)', 'Teachers (2008-09', 'Student-Teacher ratio (2008-09)', 'French enrollment (2011-12)', 'Graduation rate (2011-12)', 'Withdrawal rate (2010-11)']
Types: ['text', 'text', 'text', 'real', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Annapolis Valley Regional School Board', 'Berwick', 'Anglophone', 14141.0, 1064.0, '15.1', '7,279 (51.5%)', '89.3%', '5.3%']
SQL:

assistant: SELECT "Withdrawal rate (2010-11)" FROM "Table" WHERE "Headquarters" = 'Truro';