Germany, the UK, France, Italy, Spain, the Netherlands, Poland, Belgium, Greece, Sweden, Austria, Denmark, Portugal, Finland, Ireland and Romania combined – all EU member nations – are about equal to the US. They have a larger combined population (about 460 million v. about 310 million) but the USA certainly don’t beat them by a factor of 5 even taking population into account, more like a factor of 1.5.
Oh, and 10 divided by 2.8 is 3.6, not 5.