The graph shows estimated oil production capacity for several Gulf countries between 1990 and 2010

The bar chart illustrates the amount of oil produced in six different Gulf nations from 1990 to 2010.
It is evident that twenty years experienced an overwhelming increase in five countries while the opposite trend was true for the production of oil in Qatar. The data of Saudi Arabia was the highest variation among the six countries.
Standing at over 8 million barrels, the oil production of Saudi Arabia rose noticeably, reaching a peak of over 14 million barrels per day in 2010. By contrast, Qatar manufactured under 1 million barrels per day, followed by stability for two decades.
As can see from the chart, there was a gradual growth in oil production in Iran approximately 3 million in 1990, rising further to over 4.2 million barrels in 2010. In similarity, the others rose steadily from around 2 million to under 4 million barrels per day at the end of the period.