How old was this Bois D'Arc tree in south Fayetteville when this part of its trunk was cut?

Please click on image to ENLARGE view and try to count the rings. Keep in mind that the center of the tree had rotted out, so you may be seeing only a certain percentage of the actual growth rings. I can't guess the years that were missing.
This species may not be native this far north but was planted to create fence lines hereabouts before barbed-wire was invented.
It is a precious tree wherever it grows, however.
I got to hear testimony on Monday, January 25, 2010, of a value of this sometimes called Osage orange tree I hadn't thought about before. When it is cut, it becomes a very special kind of firewood.
The person who described this phenomenon was unwilling to repeat his comments for video but I will ask him again later to share his experience with the use of bois d'arc firewood.