First: You should explain exactly what you are plotting - dependent and independent variables, with units - and how those values were measured. Second: Ideally you would show data versus just trying to describe it. Finally, part of writing a thesis and certainly doing research is thinking about the data yourself and trying to come up with a plausible explanation for it. Sometimes this requires doing a lot of research into prior literature. If we explain your data for you, then you don't learn anything about the scientific process. If you want to propose something and get feedback, that's where Chemical Forums can help.