SCHEMA:
CREATE TABLE table_name_80 (win__percentage INTEGER, year VARCHAR, coach VARCHAR, record VARCHAR)
USER:
What is the largest win percentage when John Gartin is coach, the record is 11-0, and the year is 2009?

QUERY:
SELECT MAX(win__percentage) FROM table_name_80 WHERE coach = "john gartin" AND record = "11-0" AND year = "2009"