I did a literature review and ended up with a lot of data in the kind of "10 out of 20 studies found x while 4 out of 8 studies found y".
To be more precise; I looked up the contribution of seafood to environmental impact categories in different studies. Here is a short extraction of my data:
I would like to represent the data somehow now. For example I would like to have a graph that shows how many cases of "Fishing" contributes "33%" compared to "Processing", "Packaging" and so on.
How can I deal with the different sample sizes? Should I select a minimum number of studies to include and if yes, is there any criteria to set that limit?
I don't need to do statistics but would like to have some simple graphs to allow readers a very quick first overview.