Proof for seemingly obvious statements in thesis?

I'm currently writing a bachelor thesis in which there is a section that deals with the pros and cons of different data serialization formats. Since this is not the main focus of the thesis, I would like to limit the comparisons to include 2-3 of the most widely used formats - for instance; JSON and XML.

I know from experience that JSON and XML are two of the most widely used formats for serializing data on the web, but how can I prove a statement like that? Does it need proof to be included as a boundary/limitation of the thesis?