This week’s theme was “success”, but it’s hard to measure the kinds of success that aren’t financial. So here are some quick facts about wealth:

The average age of Forbes’s 400 wealthiest individuals is 63.

There are about 10 million millionaires in the world.

Only about 20% of millionaires inherited their wealth.

The 80,000 or so people around the world classified as “ultra-high net worth”  – i.e., possessing over $30 million in assets – have on average eight cars, three to four homes, a jet aircraft, and a yacht.