It looks like just the UK, France and Germany combined already add up to more aid with a combined GDP that’s much lower than the US. These kinds of graphs give a distorted picture due to the high population and GDP that the US has.
GDP: http://www.wolframalpha.com/input/?i=gdp+of+uk%2C+france%2C+us+and+germany
Population: http://www.wolframalpha.com/input/?i=population+of+uk%2C+france%2C+us+and+germany
I’ve been using the DS620slim for 4.5 years now without any issues. It’s small (2.5” drives) and produces little noise (with SSDs).