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_23 (evaluation_average__before_april_2009_ VARCHAR, peak_lessons_taught VARCHAR, _percentage_of_negative_evaluations VARCHAR)

### Question ###
What is the mean Evaluation number (before April 2009) when the Peak lessons taught was less than 80 and the negative percentage of evaluations was 0.8%?

### Accurate SQL ###

SELECT evaluation_average__before_april_2009_ FROM table_name_23 WHERE peak_lessons_taught < 80 AND _percentage_of_negative_evaluations = "0.8%"