Add Row with Percentage to Table visual

RolandBAV , Create measures

sales = Sum(Table[Sales Value])

Clients = distinctcount([client ID])

% of Sales = divide([sales], calculate([sales], removefilters(Table[Market Area])) )

% of client = divide([Clients], calculate([Clients], removefilters(Table[Market Area])) )

You can now use these measures on Matrix visual- With option - Switch values to row

Switch values to row - https://youtu.be/cN8AO3_vmlY?t=11650

Percent of Total and Percent of SubTotal https://www.youtube.com/watch?v=6jTildcV2ho
https://www.youtube.com/watch?v=cN8AO3_vmlY&t=24270s

Hi RolandBAV 

If you just wanted to do pivot ofyour data just take matrix visual and enable this option under value section

take your market in column section and sales and percentage in value section

I hope i answered your question!