This appears to be a layout error. According to
http://data.worldbank.org/region/ECA , $1.888T was the 2012 GDP for Europe & Central Asia (developing only). That page list the 20 small developing nations in that region which are included. However, according to
http://data.worldbank.org/region/EMU , $12.19 trillion was the 2012 GDP for the Euro area. Then, according to
http://data.worldbank.org/region/EUU , $16.69 trillion was the 2012 GDP for the European Union. Hence, the developed European nations should have been listed under one of these regions. If anyone knows of a better way to contact Google and/or if someone from Google should see this, please reply.