Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.[7] With 1.3 billion people[1][2] as of 2018, it accounts for about 16% of the world's human population. Africa's population is the youngest amongst all the continents;[8][9] the median age in 2012 was 19.7, when the worldwide median age was 30.4.[10] Despite a wide range of Natural resources, Africa is the least wealthy continent per capita, in part due to geographic impediments,[11] legacies of European colonization in Africa and the Cold War,[12][13][14][15][16] predatory/neo-colonialistic activities by Western nations and China, and undemocratic rule and deleterious policies.[11] Despite this low concentration of wealth, recent economic expansion and the large and young population make Africa an important economic market in the broader global context.