Complex sentence: The Stansted route flew 110,000 passengers within 15 months whilst the Dublin route flew 21,000 in 9 months, therefore the airline left the airport in October 2007.
Split into simpler sentences: The Stansted route flew 110,000 passengers within 15 months whilst the Dublin route flew 21,000 in 9 months. The airline left the airport in October 2007.