Most Halloween questions on GA ask for specific costumes (and where to get / how to do them) , some refer to the film series. However, theer are curious questions as well. From an answer by Tutuzdad we learn that Halloween is claimed by some to be the most ancient holiday in the world.
Hal from "Ranch Ramblins" mentions in his autumn post (with beautiful pictures!) about leaves and removing them, that:
T.L. Spiegel, the Ultimate Authority on Everything!
According to this response from Google Answers, there are approximately 200,000 leaves per oak tree (Google - the ultimate authority on everything). By multiplying 200,000 leaves times the previously derived 44,880 trees, we find that each and every year, approximately 8,976,000,000 leaves are produced on our land. Based upon the casual accuracy of these calculations, let’s just say around 9 billion leaves per year!