The oil companies, in particular, are under pressure because the number of operations in the Amazon Rainforest, one of the world's most sensitive ecosystems, is increasing. In 2006, the value of Peruvian minerals (metals, industrial minerals, and fuels) production amounted to $6.5 billion, compared with $5.1 billion in 2005. Mining and fuel production increased by 8.1% as a result of larger values of metals (7%) and fuel output (23%). The increase of mineral outputs (content) was mainly led by natural gas (77%), molybdenum (22%), gold (20%), crude oil (18%), and iron (8%), and to a lesser extent by silver and lead (4% each) compared with 2005 outputs. In 2006, metal prices were also driven upwards because of the higher consumption associated with increased world economic activity, such as in China, the United States, and other countries. Metal production growth was mainly led by an increase in copper, iron, silver, and lead, which offset the decreased output of gold, molybdenum, and zinc. The hydrocarbon sector's output also increased due to the increased extraction of natural gas at Aguaytía and Camisea. Crude oil output was expected to increase as the result of the 16 new oil exploration and production contracts signed in 2006. Peruvian laws have attempted to ensure equitable mineral, crude oil, and gas exploration and production. Owing to these terms, an increased number of domestic and foreign companies, AngloGold Ashanti, Barrick Gold Corp., BHP Billiton plc., Cambior Inc., Falconbridge Ltd., Mitsui & Co., Ltd., Mitsubishi Corp., Peñoles, Teck Cominco Ltd., and others, have expressed interest in participating in prospecting, exploration, production, and distribution of natural gas and petroleum contracts with Perupetro S.A. and mineral properties with Centromín. The structure of the Peruvian mineral industry continued to change as a result of privatizations and joint-venture projects. The establishment of consortia in such deregulated industries as oil and gas, and joint ventures in energy and mining projects were becoming a common practice in Peru. According to the Ministerio de Energía y Minas, Peru was the seventh most attractive area for investments in exploration after, in order of investment attractiveness ranking, Tasmania (Australia), Nevada and Alaska (USA), Northwest Territories (Canada), Western Australia, and Indonesia. The new operating process, which was the result of the privatization and joint-venture projects, incorporated policies that deal with economic and societal development issues and with environmental protection in a sustainable way.