Average of values for a lookup/array scenario w large data set

I'm looking at fuel consumption and CO2 emissions for all models and manufacturers of different types of classes of vehicles since 2000 (a huuuugee data set). Im trying to create a formula on my Table tab to take the average of the fuel consumption for all of the values when the year, class and fuel type is matching the same for the row. Im also trying to do this for Average CO2 Emissions (column E).

Basically, when Column A = 2013, Column B = COMPACT, Column C = D then average all the values that match those from the Example Spreadsheet tab.

Can anyone help me with this please? Thanks

Help w large data set formula.xlsx