'Please provide a source'? Read my post again and you'll see that I already provided the source. Twice. The person saying that only about 300 words (plus derivatives) derive from Proto-Finno-Ugrian is none other than Ulla-Maija Kulonen; professor at the department of Finno-Ugrian studies at the University of Helsinki. You'd be hard pressed to find a greater authority. And nobody's saying that all borrowings in Finnish are from Swedish, there's a huge number of loans from Indo-Iranian languages, Baltic languages and other borrowings as well.