Oil production capacity (graph comparing the estimated oil production /capacity)

The graph compares the estimated oil production capacity from 6 different oil countries, which recorded from 2004 to 2010.

During these periods, Saudi Arabia was taking the leading role in the selected group and its unit oil capacity ranged from 8.5million to 14.5 million per barrel annually, far beyond its competitors. Meanwhile, fairly a few chances to win the No. 2 position because of there have very slim differences between Iran, Iraq and Kuwait, as well as UAE. The unit number was estimated varied from 1.9 million to 4.5 million. Qatar was at the bottom of the line and the number for annual capacity was below 1.5 million.

In a conclusion, Saudi Arabia has gained tremendous growth in its oil production capacity whereas other 5 countries stayed at the same level. The landscape remained unchanged in the past 5 years.

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  Attaching the graph
  

The graph compares the estimated oil production capacity from 6 different oil countries which recorded from 2004 to 2010.
The way you had written this, it was as though the countries had recorded something. But I fixed it by simplifying.

During these periods, Saudi Arabia was taking the leading role in the selected group, and its unit oil ...

Meanwhile, fairly quite a few had chances to win the number two No. 2 position because of ...

In a conclusion, Saudi Arabia has gained tremendous growth in its oil production capacity, whereas the other five countries stayed ...

:-)

much appreciated, Kevin.