Average annual West Texas Intermediate crude oil prices are shown for the 1970 to 2000 period, in both nominal and real ($2009) U.S. dollars. Prior to 1973, the annual real price of crude oil (in 2009 dollars) was relatively stable, trading for most times within a narrow range of $10 to $30 per barrel. Oil prices rose starting in 1973 with the Arab Oil Embargo (1973), the Iranian revolution (1978), and the Iran-Iraq war (1980). In 1980, annual oil prices peaked at just under $100 ($2009) per barrel. Oil prices fell below $40 per barrel by the end of the 1980s, with technology improving the fuel efficiency of cars, the 1980s recession, and growing non-OPEC supply reducing oil prices. The 1990s brought the first Gulf war (1990-1991) which had an impact on supply and oil prices. However, OPEC’s lack of action kept oil prices low for an extended period. However, when crude oil prices plummeted to $10 per barrel following the Asian financial crisis (1998), OPEC instituted a series of production cuts, starting in late 1999. This allowed OPEC to regain control over the oil market, and this began to result in higher oil prices.