The price of crude oil is perhaps the most discussed issue at this time worldwide.

But how this value has evolved over the years and what were the causes of this development?

Below is a brief summary of the evolution of this price since 1970 when each barrel cost was only $3.

1973 » First oil crisis.

1979-80 » Second oil crisis

1985-86 » OPEC (Organization of the Petroleum Exporting Countries) boosts production.

1990-91 » First war in Iraq (Gulf War).

1998 » The Asian economic crisis cause OPEC output increase.

1999-2000 » OPEC lowers production while demand is high.

11 September 2001 » A series of coordinated suicide attacks by al-Qaeda upon the United States.

2002-03 » General strike in Venezuela, worries over US invasion of Iraq.

2003 » United States and allies invade Iraq.

2004 » OPEC reduces the production.

2005 » Hurricanes in Gulf of Mexico.

2006 » Concern over situations in Iraq and Iran along with heightened demand expected during US driving season.

2007 » The crude rose above $90 for the first time, due to a combination of tensions in eastern Turkey, and increasingly small value of the U.S. dollar.

January 2 2008 » A single exchange was made at $ 100, but the price didn't run above $100 until February.

June 27 2008 » Prices touched the $142.26 per barrel.

Given the current scenario who knows what will happen in the future and how this situation will evolve.