average printed in e.g. 'Average Courant Number' differs between parallel and non-parallel

Summary

average printed in e.g. 'Average Courant Number' differs between parallel and non-parallel

Steps to reproduce

run e.g. pimpleFoam with

• binary writing so we don't have any write precision issues
• non-uniform 0/U
• no 0/phi

It will now calculate the initial phi and the Courant number from that (finiteVolume/cfdTools/incompressible/CourantNo.H). I would expect it to be the same for parallel and non-parallel