eu27_region returns a vector of region representing EU27 member states. The
selection is based on the GDP of countries. If the total GDP of EU27
countries from the region is greater than 50% of total GDP of the region,
the region is considered as belonging of Europe.
See also
Other misc functions:
brazil_regions(),
china_regions(),
eu28_regions(),
eu_regions(),
europe_regions(),
india_regions(),
oecd_regions(),
region_id(),
usa_regions()
