Hi

I'm new to Tableau, using desktop v10.5.  I am wanting to create a ratio to show the extent to which a person managing a project delegates to others (based on their role).  My data contains the following columns:

Name

Grade

Project code

Units

I am wanting to display:

Grade

Units

% of total

Manager ratio

It is the manager ratio that I have not been able to achieve.  The outcome I want to achieve is as follows (and I can live without the ":1" aspect if that makes things more difficult):

I have tried different ways, and I can't get the calculation to work, and I can sort of understand why not, based on the aggregation.  My searches haven't proved successful either.  Is there a way to achieve this?  I have enclosed an example twbx file

Thanks very much

Philip