Is the tax amount at the line level in cXML the total or unit amount?

I work for an eProcurement company that integrates with it's customers in many formats, one of which is cXML.  I've recently been looking at the cXML integration type and a question that's come up is weather the tax amount at the line level should be total or unit.  I've found some examples i.e. this cut down version of the one is from the cXML documentation but I'm not sure if the numbers are just made up or not:

<ItemOut quantity="2" lineNumber="1">

  <ItemID>

    <SupplierPartID>1233244</SupplierPartID>

  </ItemID>

  <ItemDetail>

    <UnitPrice>

      <Money currency="USD">1.34</Money>

    </UnitPrice>

  </ItemDetail>

  <Tax>

    <Money currency="USD">1.34</Money>

  </Tax>

</ItemOut>

So if tax is taken at 20% should the tax amount for this example be 0.27 or 0.54?

Cheers,

Alexei Blue.