Complex sentence: While it was originally planned to use only 8 units, the unit 009 was also refurbished and transported to the island in 1992,2 years after the the rest of the fleet entered service.
Split into simpler sentences: While it was originally planned to use only 8 units, in 1992 the ninth unit was also refurbished, numbered 009, and transported to the island. It was then 2 years after the rest of the fleet entered service.