All these are figures displayed on the onboard computer. I did reset the counters before each of above travels. I believe that the computer is accurate but have no proof in hand to prove the accuracy of the computer. With the next full tank, I will verify the computer calculation against actual and will let you know the results.
However, 15.5 figure above was obtained by driving with extra attention on fuel efficiency. I have noted that, with 2.0L 406, RPMs above 2000 makes a clear difference in fuel consumption. So I never REV beyond 2000 unless there is a purpose like overtaking. On the other hand, I never hesitate to REV beyond even 4000 - 5000 if I need to quickly overtake a vehicle.