CREATE TABLE table_203_691 (id NUMBER, "week" NUMBER, "date" CLOB, "opponent" CLOB, "result" CLOB, "attendance" NUMBER)

how much higher was the attendance in week 15 as compared to in week 14 ?
SELECT (SELECT "attendance" FROM table_203_691 WHERE "week" = 15) - (SELECT "attendance" FROM table_203_691 WHERE "week" = 14)
SELECT (SELECT "attendance" FROM "table_203_691" WHERE "week" = 15) - (SELECT "attendance" FROM "table_203_691" WHERE "week" = 14)