Not sure on that, but there are more regions than just the US and UK. For instance, here in Australia a teaspoon[1] is 15ml, not 14.92ml, and a tablespoon[2] equals four teaspoons, not three, so 20ml, not 14.8ml.
[1] https://en.wikipedia.org/wiki/Teaspoon#United_States_customa...
[2] https://en.wikipedia.org/wiki/Tablespoon#Traditional_definit...