CREATE TABLE table_14603212_5 (school_year VARCHAR, class_aAAA VARCHAR, Gregory VARCHAR, Portland VARCHAR)

What are all the school years where class AAAA is in Gregory-Portland?
SELECT school_year FROM table_14603212_5 WHERE class_aAAA = Gregory - Portland
SELECT "school_year" FROM "table_14603212_5" WHERE "class_aAAA" = "Gregory" - "Portland"