"Cook dismissed the figures, telling the Irish Independent: "In the year that the commission says we paid that tax figure, we actually paid $400m. We believe that makes us the highest taxpayer in Ireland that year.”"
So he is saying they paid ~5% tax then, if they had a profit margin of 20% (which as its apple is probably more). In 2014 they generated approx $40B ($8B in profit) in revenue in Europe which went through Ireland, which they paid $400m in tax.