"four years of relative stability at around US$105 per barrel". A 2015 World Bank report said that the low prices "likely marks the end of the commodity supercycle that began in the early 2000s" and they expected prices to "remain low for a considerable period of time". Goldman Sachs, for example, has called this structural shift, the "New Oil Order"—created by the U.S. shale revolution. Goldman Sachs said that this structural shift was "reshaping global energy markets and bringing with it a new era of volatility" by "impacting markets, economies, industries and companies worldwide" and will keep the price of oil lower for a prolonged period. Others say that this cycle is like previous cycles and that prices will rise again. A 2020 Energy Economics article confirmed that the "supply and demand of global crude oil and the financial market" continued to be the major factors that affected the global price of oil. The researchers using a new Bayesian structural time series model, found that shale oil production continued to increase its impact on oil price but it remained "relatively small". Benchmark pricing Major benchmark references, or pricing markers, include Brent, WTI, the OPEC Reference Basket (ORB)—introduced on 16 June 2005 and is made up of Saharan Blend (from Algeria), Girassol (from Angola), Oriente (from Ecuador), Rabi Light (from Gabon), Iran Heavy (from Iran), Basra Light (from Iraq), Kuwait Export (from Kuwait), Es Sider (from Libya), Bonny Light (from Nigeria), Qatar Marine (from Qatar), Arab Light (from Saudi Arabia), Murban (from UAE), and Merey (from Venezuela), Dubai Crude, and Tapis Crude (Singapore). In North America the benchmark price refers to the spot price of West Texas Intermediate (WTI), also known as Texas Light Sweet, a type of crude oil used as a benchmark in oil pricing and the underlying commodity of New York Mercantile Exchange's oil futures contracts. WTI is a light crude oil, lighter than Brent Crude oil. It contains about 0.24% sulfur, rating it a sweet crude, sweeter than Brent. Its properties and production site make it ideal for being refined in the United States, mostly in the Midwest and Gulf Coast regions. WTI has an API gravity of around 39.6 (specific gravity approx. 0.827) per barrel (159 liters) of either WTI/light crude as traded on the New York Mercantile Exchange (NYMEX) for delivery at Cushing, Oklahoma. Cushing, Oklahoma, a major oil supply hub connecting oil suppliers to