Take a look at the attached workbook. It requires nested table calculations for each of the Index measures, one calc to compute the initial %, the second to compute the total %, with each measure set to a different addressing and partitioning.
If you're not that familiar with table calculations, I suggest you read the following blog and forum posts:
Let me know if this works for you!
Thank you, Jonathan! Just what I was looking for. I appreciate your help and recommendations for further reading about table calcs.