To estimate day by day ordinary prices, KAYAK usually takes all rates for every single day prior to departure during the last 12 months for flights from London Heathrow Airport to Austin, eliminates the highest 0.1% to account for outliers, then takes the common of the many values for monthly. https://businessclassflightstomiami.blogspot.com/2024/05/how-to-find-best-deals-on-cheap-flight.html