pre_text: Reconciliation of Bookings The following table reconciles total bookings to total revenue, its most directly comparable GAAP financial measure: (1) Change in deferred revenue also includes the impact of realized gains or losses from the hedging of bookings in foreign currencies.
table: Year Ended December 31,
table: 2019 2018 2017 2016 2015
table: Total Bookings: (unaudited; in millions)
table: Total revenue $2,988.1 $2,660.1 $2,231.9 $1,847.9 $1,607.3
table: Change in deferred revenue(1) 180.5 163.2 214.4 163.5 165.9
table: Net refunds 233.4 192.6 170.0 141.9 137.8
table: Other (0.8) (4.4) 1.9 2.2 3.2
table: Total bookings $3,401.2 $3,011.5 $2,618.2 $2,155.5 $1,914.2
question: Analyse this data from a financial earnings document. What is the average total revenue for 2018 and 2019?