Complex sentence: In the departure hall at that time there were 26 check-in desks, however in subsequent years of operation, passenger traffic grew rapidly--in 1993 the airport handled nearly 2.2 million passengers, while six years later, this figure climbed to 4 million.
Split into simpler sentences: In the departure hall at that time, there were 26 check-in desks; however, in subsequent years of operation, passenger traffic grew rapidly. In 1993, the airport handled nearly 2.2 million passengers, while six years later, this figure climbed to 4 million.