question: Which Year Joined has a Size larger than 93, and a Previous Conference of none (new school), and a Mascot of rebels?
answer: SELECT AVG(year_joined) FROM table_name_88 WHERE size > 93 AND previous_conference = "none (new school)" AND mascot = "rebels"
context: CREATE TABLE table_name_88 (year_joined INTEGER, mascot VARCHAR, size VARCHAR, previous_conference VARCHAR)