Writing task 1: the percentage of car sales in different regions

I'm practicing for both task 1 and task 2 of IELTS writing, please give me some comments that I can improve my skills.
Thanks a lot.

Total car sales 2006-2010

The bar chart illustrates the proportion of the big car-making company's sales in four regions: South America, North America, Asia, and Europe from 2006 to 2010.

Overall, the number of car consumption in Asia and Europe was higher than in other regions. Besides, North America and South America took a small percentage, even had a downtrend.

Firstly, in Europe, the total car sales doubled from a quarter in 2006 to a half in 2010. This made Europe become the biggest car-consuming region at the end of the period. In contrast, the sales in Asia had a slight decline while kept steady at 35 percent in 2006 and 2007 then increased to 38 percent the following year but finally went down significantly to 30 percent.

There was an obvious fluctuation in the proportion in South America at around 11 percent over the period. South America reached the lowest sale with only 5 percent in 2007. In North America, the proportion felt down gradually from less than a third to just 9 percent.

• 
  
  

Rather than using the word proportion, the more appropriate term to have used would have been percentage. That is because the summary overview feels incomplete. You did not refer to the measurement type in the presentation. Additionally, your single sentence presentation of the information summary is a run-on. Try to use 3 sentences so that you can offer a clearer, easily read, and easier to remember summary. The rest of your presentation is acceptable. However, having a long trending statement as a stand alone statement feels out of place. Mostly because it is only a 2 sentence presentation within a 3 paragraph minimum expectation. The clarity of the summary and trending statement is usually helped by combining the information into a single overview paragraph. It helps you score better in terms of task accuracy as opposed to the 4 paragraph presentation that opens you to an improper sentence presentation when considering the mix of simple and proper sentences.