Time average of scalar variable for specific block

I have simulated a transient aerofoil case in OpenFOAM. Inside the controlDict of OpenFOAM I mentioned that I need the time averaged values for velocity and pressure, but I forgot to mention that I need a time averaged value for a scalar variable. I have the data for intermediate time steps and I want to the get the time averaged value for that scalar variable. Is this possible during the postProcessing the data through Paraview? Or specifically would I be able to get the time averaged value for the scalar variable across the (block) aerofoil? Any comment/suggestion will be a great help. Thanks in advance