Your neighborhood has seen some growth in squirrel population over the past couple years. Two years ago you noticed eight squirrels living in your and your neighbor’s yards. Last year you counted $12$ squirrels. Currently, there are $18$ squirrels that live in the yards. Write an equation representing this situation. If this rate of growth continues, how many squirrels should you expect to see five years from now? Is your answer realistic? Why or why not?