VAT rate displayed on invoice PDF

Currently on our invoices we display the subtotal section at the bottom which contains lines for subtotal, VAT percentage and Total, like this:

Subtotal          xxxx
VAT (20%)      xxxx
Total               xxxx

Currently we have several if statements which determine the text displayed at the bottom, so if the subsidiary is UK and the Ship To is in the EU, VAT (20%) is displayed.  If its the Germain sub and Ship To is in the EU, VAT (19%) is displayed etc.  Currently the "20%" part of the text is hardcoded into the PDF template.

However we now have some customers with a Ship To in Germany for example that fall under the UK sub.  In these instances the invoice is displaying the "20%" value even though the actual rate used on the invoice is 19%.  Rather than hardcoding the text into the PDF template, how can I pick up the tax rate used within the invoice itself, from the first item line (all items will have the same rate) and display that instead of where it says "20%"?