The chart illustrates the Outokompu stock price ...
... the rate reached the peak in the end 2006 and almost virtually the highest score in ...
still 2 sentences, your paragraph will be weak if you only present 2 sentences in a paragraph, remember to always make a minimum THREE paragraph before moving to next one, otherwise it will give a bad effect on your band score.
three sentences can possibly contain a strong and solid paragraph rather than only using 2 sentences by using more complex sentences.
consider these changes:
The line chart illustrates.... Overall, it can be seen that.... Furthermore, the line chart virtually... (remember VIRTUALLY and ALMOST have the same meaning, pick one of them)
Following this, the stock price was a virtually steady to finish the period at 11 that the level almost back to the starting point in early 2006.
confusing sentence..
consider this:
Following this, the stock price was virtually steady to finish the period at 11, while the level almost back to the initial point in early 2006.
Overall, your writing presents the adequate information about the line graph. Keep up the Good Work! :D