Who cares how much is on the inside,just as long there is enough on the ground to follow ! I am sure that every deer has different amount of blood in their bodies, lets keep it simple folks.
Besides i have never recovered a deer that was complety drained of all its blood theres allways some left when i gut it. As long as the deer is at the end of blood trail i'll be happy!!
take your kids hunting and you wont have to hunt your kids.