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_15 (average INTEGER, number_of_dances VARCHAR, total VARCHAR)

### Question ###
What is the highest average that has 6 dances and a total of over 128?

### Accurate SQL ###

SELECT MAX(average) FROM table_name_15 WHERE number_of_dances = 6 AND total > 128