The ex SIA Boeing 777 are around 12 to 13 yr old. SIA took elivery of its first 777 in 1997.It was named as jubilee . Singapore Airlines is phasing out the Boeing 777-200 Fleet slowly with Airbus A330-300. I am not suprised as SIA has a very young fleet. I expect the 777-200 series to leave the fleet completly in another year or two. The Airbus A330 will be replacement for a few years. Ultimately The Airbus A350WXB and Boeing 787-9 will take over for long term.