Add one line of taxes in %

Hi, I have a problem with the taxes. I need deliver an invoice with taxes with the following appearance:

1 item……………….. 20 €

tax of 21 %……. 4.20 €

Total ……….. 24.20 €

Now it only shows the total cost of 24.20 but I don’t know which % has of VAT.

I hope somebody can add this function in the future update of the plugin.

http://wordpress.org/plugins/woocommerce-delivery-notes/