Edinburgh Trams has seen a nine per cent rise in passengers in its second 12 months of operation. 

New figures show 5.38 million passengers used the service - an increase on the 4.92 million who got on board during its first year. 

The controversial line marked its second birthday at the end of last month. 

It was officially launched at 5am on May 31, 2014. 

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Transport bosses said passenger numbers were about 340,000 ahead of target. 

And they insisted the service had raked in six per cent more revenue than expected - with full details of the company's performance due to be released in the summer. 

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Tram general manager Lea Harrison said: "The trams are a convenient, comfortable and cost-effective way of travelling through the city and we're delighted to see this reflected in our passenger figures. 

"We'll continue to work hard at providing the best possible service and to introduce further improvements to encourage even more travellers to hop on board." 

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Concessionary card holders currently account for 8.2 per cent of passengers, which bosses argue is well within the council's budget. 

Operating with 99 per cent service reliability, the trams recently received a 97 per cent overall customer satisfaction rating following an independent, UK-wide survey by Passenger Focus. 

And a good year was topped off when the service picked up a Certificate of Excellence from travel review site TripAdvisor. 

George Lowder, the chief executive of Transport for Edinburgh, said the results were "hugely encouraging". 

He added: "I am extremely grateful to all the staff at Edinburgh Trams for their dedication and hard work that provides such an excellent service as recorded in the 2015 Passenger Focus Survey and by TripAdvisor. 

"We are concentrating this year on enhancement of the existing service and are certainly not going to be complacent." 

Cllr Lesley Hinds, chair of Transport for Edinburgh and the city's transport leader, added: "There is no doubt Edinburgh Trams is going from strength to strength, as these latest passenger figures show, alongside consistently high customer satisfaction ratings. 

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"This is thanks to a great team of staff, who over the last two years have helped make Edinburgh Trams the service it is today, and I look forward to continuing our journey as it develops and expands." 

Edinburgh Trams has a fleet of 27 vehicles and currently employs 130 staff including drivers, ticketing assistants, control centre operators and maintenance engineers. 

Following a troubled construction process, the 8.7-mile line opened three years late. 

Delivery was mired in ballooning costs, which are thought to exceed £1 billion once interest payments are factored in.