Show the average ticket prices for exhibitions for all years before 2009?
select avg ( ticket_price ) from exhibition where year < 2009
Show minimum ticket prices for exhibitions for all years before 2009?
select min ( ticket_price ) from exhibition where year < 2009
Show maximum ticket prices for exhibitions for all years before 2009?
select max ( ticket_price ) from exhibition where year < 2009
Show average ticket price for exhibitions for year 2005?
select avg ( ticket_price ) from exhibition where year = 2005
Show average ticket price for exhibitions for all years before 2006?
select avg ( ticket_price ) from exhibition where year < 2006