To calculate monthly normal selling prices, KAYAK normally takes all costs for on a monthly basis over the past calendar year for round-journey flights from London to Atlanta, removes the highest 0.one% to account for outliers, and then can take the median of all values for on a monthly basis. https://flightstovegasfromuk.family.blog/2024/10/24/what-are-the-benefits-of-volunteering-while-you-travel/