Hai, let's start with your mistakes in using English terms. A century is equivalent to 100 years. 50 years is equivalent to half a century. Make sure you know the correct word usage before you use the term as the proper usage will increase your LR score while improper usage will tremendously decrease your LR score. If you are not sure of how to properly use a word, find an alternative for it. Since you are practicing for the test, use a dictionary to learn the meaning of the word before you use it. Memorize the meaning and use it when appropriate.
The graph shows the years of 1900, 1950, 2000, and 2050 as a projection. These are separate half century considerations and should not have been termed as "between 1990 and 2050". Rather, only the inclusive dates indicated in the graph should have been specifically mentioned. That is because a Task 1 essay requires factual analysis of actual data presented from the essay. So when specific information is provided, it must always be represented in the analysis report.
In your final paragraph, you mentioned:
There will be thirty five out of one hundred people in this region ...
Where did the figure for 35 out of 100 come from? There is no mention of this figure in the chart. Therefore, you are guessing and presenting information not based on the data you were provided with. This creates an inaccurate report and will affect your TA score. If the information is not clearly stated or implied in the chart, it should not be in your report either.
There is a lacking comparative analysis of the identical information for the population of the suburban and urban area in 1900 and 2050. That is something that is not indicated in your report, but, as part of the analytical presentation, could have increased your score because that would create a thorough analytical report on your end. Minute details that may be overlooked, as indicated in the chart will always help your score. Making up the information won't.