  In this article we discuss the requirements needed in order to characterise
the solution space of perturbed linear integrodifferential Volterra convolution
equations. We highlight how integrodifferential equations react far better
under perturbations than their integral equation counterparts in regards to
stability of solutions. To illustrate this idea we give a characterisation of
when the Ces\`aro mean of solutions converge to a limit, which is explicitly
identified and given in terms of the problem data. Additionally we note how all
results can also be applied to functional differential equations.
