That is a lot of oil in between oil changes!! I would go to your Toyota dealer and explain to them your oil usage. You actually might not need an oil usage test. Using this much oil the engine is likely leaking it somewhere else.
1) It could be leaking the oil while the vehicle is in motion, and not leaving droppings on the driveway
2) It could be leaking the oil on the driveway
3) It could be burning the oil - perhaps you have seen some smoke behind your vehicle? Also check exhaust at end of car for oil residue.
You did not mention how many miles on your vehicle. I'm guessing that since it is 10 years old, and the average miles per year is 15,000; than you should have approximately 150,000 miles. Is this close?