What year was the brabham bt46 bt48 bt49 Chassis common?
CREATE TABLE table_name_89 (year INTEGER, chassis VARCHAR)
SELECT AVG(year) FROM table_name_89 WHERE chassis = "brabham bt46 bt48 bt49"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_89 (year INTEGER, chassis VARCHAR) Question: What year was the brabham bt46 bt48 bt49 Chassis common? [/INST] SELECT AVG(year) FROM table_name_89 WHERE chassis = "brabham bt46 bt48 bt49" </s>