Presented is the bar chart exhibiting the changes in the amount of oil produced in six different Gulf nations over a 20-year course commencing 1990.
As transparent from the chart, the oil production capacity of all Gulf countries demonstrates an upswing trend over the survey period. Also noteworthy is that Saudi Arabia maintained and strengthened its position as the major producer.
In 1990, Saudi Arabia’s oil generation capacity accounted for the highest percentage, with practically 9 million barrels per day, and then there was a surge to roughly 12 million in 2005. During the subsequent 5 years, the figure rose significantly and eventually hit a peak of over 14 million, being virtually two-fold its capacity in the initial year. By contrast, with its oil production capacity starting at a modest figure of 1 million, Qatar registered an insignificant increase throughout the given period.
Roughly 3 million barrels per day was produced in Iran in 1990, the figure underwent a gradual rise to 4 million per day at the end of the period. A similar pattern was also recorded in the remaining Gulf countries. 
Presented is the bar chart exhibiting the  
changes
 in the amount of  
oil
 produced in six  
different
 Gulf nations over a 20-year course commencing 1990.
As transparent from the chart, the  
oil
 production  
capacity
 of all Gulf countries demonstrates an upswing trend over the survey period.  
Also
 noteworthy is that Saudi Arabia maintained and strengthened its position as the major producer.
In 1990, Saudi Arabia’s  
oil
 generation  
capacity
 accounted for the highest percentage, with  
practically
 9  
million
 barrels per day, and then there was a surge to roughly 12  
million
 in 2005. During the subsequent 5 years, the figure rose  
significantly
 and  
eventually
 hit a peak of over 14  
million
, being  
virtually
 two-fold its  
capacity
 in the initial year. By contrast, with its  
oil
 production  
capacity
 starting at a modest figure of 1  
million
, Qatar registered an insignificant increase throughout the  
given
 period.
Roughly 3  
million
 barrels per day  
was produced
 in Iran in 1990, the figure underwent a gradual rise to 4  
million
 per day at the  
end
 of the period. A similar pattern was  
also
 recorded in the remaining Gulf countries.