CREATE TABLE table_21514460_1 (withdrawal_rate__2010_11_ VARCHAR, headquarters VARCHAR)

What is their withdrawal rate for the school district with headquarters located in Truro?
SELECT withdrawal_rate__2010_11_ FROM table_21514460_1 WHERE headquarters = "Truro"
SELECT "withdrawal_rate__2010_11_" FROM "table_21514460_1" WHERE "Truro" = "headquarters"