CREATE TABLE table_13974 ("Country" TEXT, "Airport" TEXT, "City" TEXT, "2008" FLOAT, "Change  ( 08/07 ) " TEXT)

Which 2008 has a City of durban?
SELECT AVG("2008") FROM table_13974 WHERE "City" = 'durban'
SELECT AVG("2008") FROM "table_13974" WHERE "City" = 'durban'