Original sentence: From a peak of 40% in 2001, BA's share of Gatwick slots will have declined by 50% to only 20% by summer 2009.In April 2009, Aer Lingus, the Irish national carrier, based four aircraft at the airport, operating to Dublin, Knock, Málaga, Zürich, Munich, Nice and Faro.It expects to double the number of aircraft based at Gatwick from 4 to 8 within 12 months.It is the airline's first base outside of the island of Ireland.Ryanair operated its first routes linking Gatwick with Continental Europe on 18 December 2008 with aircraft stationed at its continental bases
Edited sentence: From a peak of 40% in 2001, BA's share of Gatwick slots will have declined by 50% to 20% by summer 2009