To me, erzeugen implies a slightly more thorough involvement than erstellen. Corresponding English translations that preserve this nuance would be erzeugen → create and erstellen → compile. The former implies the product is made from a much more basic input. For example, you would never use erzeugen in the context of building a physical object and you would never use erstellen in the context of biological creation (e.g., babies). (Note, however, that either word is rarely used in these example context and usually an altogether different word is used.)
In your specific context, I would use erstellen if the program only compiles some source data (which seems to be the case), while I would use erzeugen if the program actually generates the data. For example, for a random number generator, I would use erzeugen, while for a plotting program, I would use erstellen.
The authors of the Duden support my perception: erstellen, erzeugen. Keep in mind, that all this is only a nuance, and both versions are most likely to be understood as intended.
PS: If you want to emphasize that the software only compiles the data, you might consider using zusammenstellen.