To put it in a nutshell,
This item is highly common.
Use these less common lexical items:
The aforementioned evidence examines that ...
Given this evidence, it can be seen that ...
When you write firstly, secondly, lastly to mention supporting points , I am afraid that you are overusing the linking devices. I think the better way is to avoid using lots of the connective words. If you think that you need to earn coherence and cohesion, pay particular attention to demonstrate cohesion.
A helpful tip before taking the exam:
When you deal with IELTS, the first thing the assessor sees is your layout, which shows whole of your essay. If the layout is difficult to read, which is let's say: no spaces between paragraphs, then he/she immediately knows your writing needs more work to read.
Hence, I suggest you to leave one space every time you open a new paragraph.