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 manufacturer ( num_of_shops INTEGER, Num_of_Factories INTEGER, open_year INTEGER )

### Question ###
what is the average number of factories and maximum number of shops for manufacturers that opened before 1990.

### Accurate SQL ###

SELECT MAX(num_of_shops), AVG(Num_of_Factories) FROM manufacturer WHERE open_year < 1990