In 2013, the economy was reported to be dependent on foreign aid and illegal resource extraction from the DRC. The largest contributor to Kigali's economy is the service sector. The World Bank estimates that services contributed 53 per cent of GDP in 2014, while a 2012 study by Surbana International Consultants put the figure at almost 62 per cent. Activity within the service sector includes retail, information technology, transport and hotels, and real estate. The city authorities have prioritised business services for expansion, constructing several modern buildings in the CBD such as the Kigali City Tower. Attracting international visitors is a priority for both the city and the Rwanda Development Board, including leisure tourism, conferences and exhibitions. Kigali is the major arrival point for tourists visiting Rwanda's national parks and tracking mountain gorillas, and has its own sites of interest such as the Kigali Genocide Memorial and ecotourist facilities, as well as bars, coffee shops and restaurants. Expansion of destinations by carrier RwandAir and building of new facilities such as the Kigali Convention Centre has attracted events to Kigali including the African Development Bank's 2014 Annual General Assembly, and a 2018 extraordinary summit of the African Union. The Commonwealth Heads of Government Meeting was scheduled to be held in the city in June 2020, with attendees including Charles, Prince of Wales, and national leaders, although this has been postponed as a result of the coronavirus pandemic.