There is an island in the Adirondacks with a population of 89 rabbits. Each year 48 rabbits are born. Ten baby rabbits are eaten by snakes on the island, 25 rabbits are eaten by wolves, 7 die of old age, 4 are inadvertently stepped on by moose and killed, and 2 drown trying to escape from wolves. What is the average age of a rabbit on this island?