I can't offer a suggestion about this plant living longer. I planted one just to have one. Mine is 22 years old, quite large, and survived the horrible 2011 drought without any help from me. After learning of the problems of the branches growing from one spot on the trunk (which is a characteristic of this tree), I started pruning it while young so that the branches developed at random along the trunk. Today that particular characteristic is not a feature of my tree although the overall shape of the tree is the "pear shape". The tree may not live many more years, but I believe it will reach old-age without branches breaking away from the trunk.