Calculate % of Subitems for same Client

Hello All, I want to calculate the percentage of subitems for a Client. In the screenshot below I want to add a column that takes for example what % is M/V VIKING SUN ($30,545.6) of the total for the Client ($118,930.9). This table is showing just one Client of many Clients. Can anyone help me with the way to do this?

Thanks in Advance,

Michael