According to 2006 estimates by the Oil and Gas Journal (OGJ), Nigeria is the seventh largest Natural Gas reserve holder in the world and the largest in Africa. In October 2004, Nigeria announced that its natural gas reserves could be as high as 660 Tcf. The government plans to raise earnings from natural gas exports to 50 percent of oil revenues by 2010. However, the Nigerian National Petroleum Company (NNPC) estimates that $15 billion in private sector investments is necessary to meet its natural gas development goals by 2010. The vast majority of natural gas found in Nigeria is associated, meaning that it occurs in Crude Oil reserves as free gas. Because many of the fields lack the infrastructure to produce the associated natural gas, it is flared. Nigeria flares more natural gas than any other country in the world, with 43 percent of its total annual natural gas production being flared. NNPC estimates that Nigerian flared natural gas accounts for approximately 20 percent of the world total. Nigeria is working to end natural gas flaring by 2008. However, Shell announced in its 2004 People and Environment Annual Report that it would not be able to meet the 2008 goal of eliminating natural gas flaring.