For this dataset, “chocolate” comprises preparations with sugar, milk, or other fats in bulk form (block, slab, or bar); and sweetened cocoa powder.
The US Department of Agriculture says that “North American Free Trade Agreement partners Canada and Mexico are not only the main destinations for US exports but also the main suppliers of chocolate candy to the US market.”
But that doesn't necessarily mean that Canada's and Mexico's strong presence is because of NAFTA — does it?