Hi Mariana, I am gonna try reviewing your writing. Hopefully, these can finalize yours.
Firstly, Be careful of deciding an overview. You have presented the overview, but your interpretation was inappropriate.
During the time, students became more interested in other languages than them past generations
You said that the students tended to learn the other language in 2010 although the percentage of the category "no other language" increased in 2010. You have to analyze the data better so that you can obtain a higher score. The overview is a point for assessing your writing. Besides that, you avoid mentioning the percentage because it will seem as the detailed information. You can pour the detailed data in the body paragraph, not in the introduction.
Secondly, you should remember that the good paragraph consists of more than 2 sentences. Actually, you don't need to separate the information into 3 paragraphs of body. We should admit that systematic can affect the coherence and cohesion in the writing. Apart from all, I only remind you that your job in the writing task 1 of IELTS is to compare figures each other, not to describe separately. It is sense of the writing task. I suggest you read many examples of writing task 1 to get the points which you should include.
I really believe you can master this section on condition that you wanna practice again and again. Happy writing
GOOD LUCK