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_24620684_2 (us_national_average_electric_mix VARCHAR, vehicle VARCHAR)

### Question ###
When bmw activee is the vehicle type what is the u.s national average electric mix?

### Accurate SQL ###

SELECT us_national_average_electric_mix FROM table_24620684_2 WHERE vehicle = "BMW ActiveE"