Table schema:
CREATE TABLE table_22308881_2 (in_county_tuition_per_credit_hour__fall_2009_ VARCHAR, college VARCHAR)

Question: How much was the in-county tuition per credit hour at the Mercer College by the fall of 2009?
SQL: SELECT in_county_tuition_per_credit_hour__fall_2009_ FROM table_22308881_2 WHERE college = "Mercer"