I didnt just calculate it. That's a rough estimate off my head and it is either 100% accurate, or extremely close to accurate.
I believe 45 versatility rating is exactly 5% versatility.
45+45=90 versatility rating
90 versatility rating=10% versatility (frame of reference)
40+40=80
80 versatility rating=8.20% (rough estimate - give or take .10%)
40 versatility=4.10%