Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_88 (average INTEGER, rank_by_average INTEGER)

### Question ###
What is the average when the rank by average is more than 12?

### Accurate SQL ###

SELECT SUM(average) FROM table_name_88 WHERE rank_by_average > 12