I have metropolitan areas and I want to calculate average values (GDP, Population, etc) per year. I have another layer with NUTS areas with theses values, from 1970 to 2012.
So far, I know the operation "join attributes by location" to calculate for example the average of GDP per inhabitant or the sum of the population, but I have to repeat the operation for each year.
Is there a way to do it automatically ? Or even better, to get the percentage of the area for each NUTS polygon layer ? Like metropolitan area MA1 is 40% NUTS N1, 55% N2 and 5% N3, so I would be able to calculate the averages and the sums.
I am a beginner with QGIS. I apologize if the question has been already answered, I have not found anything so far about that.