Raymond,
It would be good if your exam scores were consistently getting a bit better with each exam but that isn't always the case, even with intensive study and wasn't the case for me either. As it says in the disclaimer, "passing" scores on the simulated exams do not necessarily lead to a passing score on the actual exam. There is just no way to say with certainty that someone is "ready" for the exam. Only you can know if you feel ready to take the exam. It would be helpful if you could also share a bit about what you are studying, how you are studying etc.. to have a better idea if you are well prepared for the exam. For example, do you have your brain dump down pat in less than 12-15 minutes? Have you been carefully reviewing your previous exam answers to gain further understanding, particularly in your weaker areas? Let us know and if we don't hear from you before your exam, I wish you the best of luck.
Cheers,
Mark