How will Europe's population grow by 2100? Most cities in the EU are expected to see surges in population growth, while a few might shrink.
These maps show the population density of several countries, using 3D spikes to denote where more people live.
The total U.S. GDP stands at a whopping $21 trillion, but which metro areas contribute to the most in terms of economic output?
Did you know that the Top 20 metropolitan areas in the U.S. contribute 52% of the total country's GDP? See how it breaks down by city...