I don’t know if leaves have a different ratio of CBDs compared to the bud, I don’t think they do, just lower amounts of all active constituents than the buds. But the actual amount of CBD is not really changed depending on being dry or not. I would think you would want to look into local medical marijuana outlets and see where they have their product tested. It is not a simple thing and often a sample amount will need to be submitted to some local laboratory. From what I understand it is not an easy thing to find a lab that can test because of legal reasons and the testing equipment is not just something you can find just anywhere. I would do a google search on your topic and do some hefty investigation.
Maybe someone else here has heard of some good places to look into and can chime in