The bar chart illustrates the estimated amount of oil produced in 6 countries between 1990 and 2010, measured in millions of barrels per day.
Overall, oil production capacity tended to increase during this 20-year period. The figures for Saudi Arabia were significantly higher than in the other countries, while production was lowest in Qatar.
From 1990 to 2010, there was a significant increase in oil production in Saudi Arabia. In 1990, just over 8 million barrels per day were produced and this rose steadily, reaching a peak of over 14 million barrels per day in 2010. In contrast, the smallest producer was Qatar. Despite a slight increase in 2000, production in Qatar remained relatively stable at less than 1 million barrels per day.
The other countries saw a slight rise in oil production over the period. The estimated figure for Iran in 1990 was over 3 million barrels per day, compared with around 2 million barrels in the other three countries. Although production did not increase in 2000 in the UAE, the amount of oil produced peaked in 2010 in Iran at over 4 million barrels and at almost 4 million barrels in Iraq, Kuwait and the UAE. 
The bar chart illustrates the estimated amount of  
oil
 produced in 6  
countries
 between 1990 and 2010, measured in  
millions
 of  
barrels
 per day. 
Overall
,  
oil
  production
 capacity tended to  
increase
 during this 20-year period. The figures for Saudi Arabia were  
significantly
 higher than in the other  
countries
, while  
production
 was lowest in Qatar.
From 1990 to 2010, there was a significant  
increase
 in  
oil
  production
 in Saudi Arabia. In 1990,  
just
  over
 8  
million
  barrels
 per day  
were produced
 and this rose  
steadily
, reaching a peak of  
over
 14  
million
  barrels
 per day in 2010.  
In contrast
, the smallest producer was Qatar. Despite a slight  
increase
 in 2000,  
production
 in Qatar remained  
relatively
 stable at less than 1  
million
  barrels
 per day.
The other  
countries
  saw
 a slight rise in  
oil
  production
  over
 the period. The estimated figure for Iran in 1990 was  
over
 3  
million
  barrels
 per day, compared with around 2  
million
  barrels
 in the other three  
countries
. Although  
production
 did not  
increase
 in 2000 in the UAE, the amount of  
oil
 produced peaked in 2010 in Iran at  
over
 4  
million
  barrels
 and at almost 4  
million
  barrels
 in Iraq, Kuwait and the UAE.