Institute, the lack of infrastructure in many developing countries represents one of the most significant limitations to economic growth and achievement of the Millennium Development Goals (MDGs). Infrastructure investments and maintenance can be very expensive, especially in such areas as landlocked, rural and sparsely populated countries in Africa. It has been argued that infrastructure investments contributed to more than half of Africa's improved growth performance between 1990 and 2005 and increased investment is necessary to maintain growth and tackle poverty. The returns to investment in infrastructure are very significant, with on average 30–40% returns for telecommunications (ICT) investments, over 40% for electricity generation, and 80% for roads. In Africa, it is argued that to meet the MDGs by 2015, infrastructure investments would need to reach about 15% of GDP (around $93 billion a year). Currently, the source of financing varies significantly across sectors. Some sectors are dominated by state spending, others by overseas development aid (ODA) and yet others by private investors. In sub-Saharan Africa, the state spends around $9.4 billion out of a total of $24.9 billion. In irrigation, SSA states represent almost all spending; in transport and energy a majority of investment is state spending; in Information and communication technologies and water supply and sanitation, the private sector represents the majority of capital expenditure. Overall, aid, the private sector and non-OECD financiers between them exceed state spending. The private sector spending alone equals state capital expenditure, though the majority is focused on ICT infrastructure investments. External financing increased from $7 billion (2002) to $27 billion (2009). China, in particular, has emerged as an important investor. Colonialism The principal aim of colonial rule in Africa by European colonial powers was to exploit natural wealth in the African continent at a low cost. Some writers, such as Walter Rodney in his book How Europe Underdeveloped Africa, argue that these colonial policies are directly responsible for many of Africa's modern problems. Critics of colonialism charge colonial rule with injuring African pride, self-worth and belief in themselves. Other post-colonial scholars, most notably Frantz Fanon continuing along this line, have argued that the true effects of colonialism are psychological and that domination by a foreign power creates a lasting sense of inferiority and subjugation that creates a barrier to growth and innovation. Such arguments posit that a new generation of Africans free of colonial thought and mindset is emerging and that this is