Avarage L/100 km wrong in my case. Why?

[Tutelarix]

I think the avarage L/100 km statistic is wrong. Check my page. I have the max L/100 km is 8.2; How the avarage can be 8.4?? Look detailed in more inside.

So,
Let's calculate avarage gas mileage for my car.

(7.3+7.6+8.2+7.1+7.3)/5=7.5 This is avarage mileage.

Let's calculate using the odometer km and liters.
I know that full gasoline tank is 55 liters. So, last time I fueled up on 46 liters, so there was 9 liters in tank.

So, I need to sum all my liters, take away 9 liters. I will get the liters of gas that I used for the last fuel up. And divide this number on last odometer number.

So:
30+42+45+51+25+41-9 = 225 liters.
The litters I used for 2985 km.
225/2985 = 0.07538
0.07538 * 100 = 7.54 L/100 km

This result is the same to my calculations with avatage milega, but in is not similiar with your results.

Please, check your calculation alghoritm, or write pls, where I wrong.

My e-mail is in profile http://www.fuelly.com/driver/tutelarix.

Thank you.