CREATE TABLE table_204_872 (id DECIMAL, "name" TEXT, "completed" TEXT, "architect" TEXT, "location" TEXT, "year of listing & ref ( s ) " DECIMAL)

what is the difference , in years , between the completion dates of 53 king street and castlefield congregational chapel ?
SELECT ABS((SELECT "completed" FROM table_204_872 WHERE "name" = '53 king street') - (SELECT "completed" FROM table_204_872 WHERE "name" = 'castlefield congregational chapel'))
SELECT ABS((SELECT "completed" FROM "table_204_872" WHERE "name" = '53 king street') - (SELECT "completed" FROM "table_204_872" WHERE "name" = 'castlefield congregational chapel'))