My go-to for numbers like these is always the wonderful Michael Moore, here is his
Materia Medica. There are tons of valuable and free texts available on his website...I could get lost in there for hours and days!
As for fresh vs dry, I've always understood the numbers given to be the percentage of alcohol that you have at the end of the tincturing process. That means that you need to take into account the amount of water in the plants when you are doing fresh tincturing (with dry herbs, the alcohol percentage you start with should be the same you end up with). That's why so many people use everclear for their fresh tinctures - because the water in the plants is going to lower the final proof of your tinctures. There are ways you can mitigate this if you don't have everclear on hand, mostly by letting the plant material wilt for a day or so before tincturing, to remove some of the water.
All that being said, I think Steven is right. As long as you end up with something that has at least 30% alcohol in it, it will be shelf stable, and you are going to get a lot of the good medicine from the herb even without a perfect alcohol percentage.