While tailgating occurs all year long at various sports events and concerts, it kicks into high gear during football season. Whether you're a novice or experienced with parking lot parties, you're sure to impress friends with your knowledge of the following tailgating trivia.

1. More than 20 million Americans tailgate in a stadium parking lot annually. Source: American Tailgaters Association (ATA).

2. 30% of tailgaters don't go into the stadium. Source: ATA.

3. The average tailgater is male, between 25-44, and college educated. Source: The Tailgating Institute of America (TIA).

4. 51% of tailgaters set up 3-4 hours before the game. Source: TIA.

5. What's the origin of tailgating? There are three stories. The first story dates back to 1869 at the first-ever college football game between Rutgers and Princeton. According to the legend, fans traveled by carriage, grilling at the "tail end" of the horse. The second story dates from 1904 at Yale. Fans came via train and walked to the stadium where they arrived hungry and thirsty. Someone decided to bring along a picnic basket to the next game and so tailgating began. The more credible story, however, is that tailgating began in Green Bay in 1919. Farmers would line up their pickup trucks along the edge of the field, drop their tailgates and eat while watching the game, hence the name tailgaters.

6. The top items purchased for tailgating: cooler, grill, beverages, chairs, meat. Source: CNBC.

7. The word barbecue appears to have originated from the Caribbean barbacoa, meaning sacred fire pit. Traditionally it involved digging a hole in the ground, placing meat in it, covering it with leaves and coal and lighting it. Cooking took several hours. Source: National Barbecue Association (NBBQ)

8. Think hamburgers originated in Hamburg? Think again. While ground meat may have begun in Germany, the first official hamburger on a bun appeared at the 1904 Louisiana Purchase Exposition in St. Louis, Missouri, also the birthplace of the ice cream cone. Source: Big Site of Amazing Facts.

9. Why does Swiss cheese have holes? The holes are created by the release of carbon dioxide during the ripening process. Interestingly, USDA regulations state that the holes in Swiss cheese must be between 11/16 and 13/16 inches in diameter. Source: AskDrGourmet.com.

10 Tailgating creates mountains of trash. While it varies, it's safe to say a lot is left behind. For example, at a recent University of Missouri football game, volunteers collected 2.01 tons of containers including?

Aluminum: 523 pounds or 19,829 cans

Glass: 3,226 pounds or 7,192 bottles

Plastic: 261 pounds or 5,540 bottles

Another 3,146 pounds of plastic was collected inside the stadium by the cleaning crew. (Source: GreenAnswers.com)