IELTS composition is not an academic paper, and the accuracy and authenticity of the content are not its focus. Of course, articles should not make low-level mistakes, including common sense and current affairs. Its focus is on English application ability, logical thinking expression ability and certain creativity. In this sense, as long as your "data" is meaningful, logical and does not violate common sense.

The question is, is it necessary for you to fabricate data? It is meaningless and contrary to common sense to fabricate a data that everyone does not believe.

If your article is only a narrative of a story, then the so-called "data" is also part of the story creation. Your writing is not a fabrication of data-the whole story is a fabrication. Even so, don't make mistakes in logic and common sense.