EU facts: What would leaving mean for trade?
...These WTO tariffs range from 32 per cent on wine, to 4.1 per cent on liquefied natural gas, with items like cars (9.8 per cent) and wheat products (12.8 per cent) somewhere in between.
John Springford, an economist with the Centre for European Reform, the total cost of those tariffs would be large, ranging from a 2.2 per cent of GDP (£40 billion) to 9 per cent.