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_82 (year INTEGER, tyres VARCHAR, chassis VARCHAR)

### Question ###
How many years were g Tyres and Minardi m187 used?

### Accurate SQL ###

SELECT AVG(year) FROM table_name_82 WHERE tyres = "g" AND chassis = "minardi m187"