 The metropolitan governments aimed to offset colonial expenditure and attain primary commercial products from Africa at a significantly reduced rate.This was successful for British commercial interests in Ghana and Nigeria, which saw a 20-fold increase in the value of foreign trade between 1897 and 1960 due to the promotion of export crops such as cocoa and palm oil.Such economic growth occurred at the expense of indigenous communities, who had no say over which crops were produced and retained marginal profits from their agricultural output.