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_41 ( evaluation_average__before_april_2009_ VARCHAR, _percentage_of_negative_evaluations VARCHAR, evaluation_average__from_april_2009_ VARCHAR )

### Question ###
What is the mean Evaluation number (Before April 2009) when the percentage of negative evaluations was 0.8% and the mean Evaluation number of April 2009 was 4.2?

### Accurate SQL ###

SELECT evaluation_average__before_april_2009_ FROM table_name_41 WHERE _percentage_of_negative_evaluations = "0.8%" AND evaluation_average__from_april_2009_ = "4.2"