To work out each day ordinary prices, KAYAK takes all prices for day after day before departure over the past 12 months for first class flights to Sydney, eliminates the top 0.one% to account for outliers, then takes the standard of many of the values for on a monthly basis. https://businessflightshop.co.uk/blog/pick-exclusive-vacation-package-in-copyright-cheapest-business-class-flights/