In 2000, international aid agencies procured an estimated US$50 billion worth of goods and services for worldwide development and relief projects. The United Nations (UN) system accounted for US$3.7 billion of this total. Constantly growing and diversifying, the portfolio of goods, equipment and commodities procured by international aid agencies ranges from grains, cereals and agricultural equipment, to water supply and sanitation, shelter and domestic items, medical and transport equipment, office equipment and supplies and fuels.