CREATE TABLE table_61531 ("Bow number" TEXT, "Ship name" TEXT, "Launched" TEXT, "Commissioned" TEXT, "Service" TEXT)

When was the ship BRP Miguel Malvar commissioned?
SELECT "Commissioned" FROM table_61531 WHERE "Ship name" = 'brp miguel malvar'
SELECT "Commissioned" FROM "table_61531" WHERE "Ship name" = 'brp miguel malvar'