Writing about a line graph with a future prediction.
Here is a line graph from the Cambridge IELTS 9 book about US energy consumption by fuel type. As you can see, there is a date range from the past with predictions for the future. Always take around 2 minutes to analyse the task before writing anything. Give yourself 4 minutes in total to plan out what you will write.
Note that this graph is courtesy of the Cambridge IELTS 9 practice book. Only use authentic Cambridge IELTS material when practicing. You can get these books online such as Amazon.com. You can also download free practice tests from ielts.org or the British Council website.
Source: Cambridge IELTS 9