Find the average number of staff working for the museums that were open before 2009.
CREATE TABLE museum (num_of_staff INTEGER, open_year INTEGER)
SELECT AVG(num_of_staff) FROM museum WHERE open_year < 2009
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE museum (num_of_staff INTEGER, open_year INTEGER) Question: Find the average number of staff working for the museums that were open before 2009. [/INST] SELECT AVG(num_of_staff) FROM museum WHERE open_year < 2009 </s>