Hoang, you have to remember that the Task 1 essay has a standard format that you have to follow in terms of presentation. This has a required 4 paragraph presentation requirement. So while you did write an acceptable 168 words, the fact that you did not split the information up into the required separate report information paragraphs will lower your score in terms of TA considerations.
You did a good enough job with the opening summary. but you forgot to include the type of passengers used for the survey (paying passengers) and the source of the survey (FAA - Federal Aviation Authority). Including these 2 pieces of information as part of the overview summary would have completed the informative presentation of the important data supplied in the chart.
There are some grammatical issues that show that you are not yet familiar with the how and when to use connecting words. An example of this problem is:
The dramatic growth kept ...
- The dramatic growth continued for one year, peaking at approximately...
The term airport is not a proper noun and should not be capitalized.
This being a task 1 essay, you are not required to present a concluding statement. You are not being asked for an opinion in this essay. You are only offering a summarized report analysis. So a personal conclusion on your part is not necessary. If you would like though, you could present your trending statement as the final paragraph (4th paragraph) instead.
If I were to write this essay, I would have used the 2012 and 2011 figures as one of the stand alone paragraphs. I would have chosen to compare these 2 lowest paying passenger events at the airport to show that the clients of the airport had a more or less 50% passenger traffic difference at the start. By the way, the assumption in the Task 1 essay is that the examiner will not have access to the actual figure, so you not change the numerical data as indicated in the chart. The numbers provide the accuracy of the report so doing your own math will tend to confuse the reader rather than inform the reader.
I hope you can follow the 4 paragraph format when you write your next practice test. You have a good eye for detail and you have the ability to truly analyze the information being presented instead of just enumerating the data to complete the word count. That is the ability to have to develop in this task so that you can score higher in the overall consideration.