How the other half lives: Some stats on the super-rich

Following the sudden death of his father last month, twenty-five year old Hugh Grosvenor became the seventh Duke of Westminster and effectively 'inherited half of London', as well as becoming one of the world's youngest billionaires.

The baby-faced Duke joins only nine other billionaires under the age of thirty, the youngest being Alexandra Andresen who, aged just twenty, already has a $1.2 billion fortune to her name. While that sounds like more than enough for anybody, she only makes it into 1,476th place in terms of wealth according to the Forbes list of billionaires. She's a very long way behind Bill Gates, who with $75 billion in the bank tops the list and remains the world's richest individual.

So which countries can boast the greatest numbers of billionaires? Well, perhaps unsurprisingly, the United States is miles out ahead at number one - here's how the list of top twenty countries stacks up:

 We also thought it would be fun to dig a little deeper into these figures and see which top twenty cities attract the greatest number of billionaires. When money is no object, where do the super-wealthy choose to live?

It's often said that half of all global wealth is held by just 1% of the population, and while the number of billionaires worldwide continues to grow, the gulf between those with extreme wealth and those living in extreme poverty continues to widen. According to the World Bank, almost 13% of the world's population lives in extreme poverty on less than $1.90 a day, with almost half to be found in China and India, placed second and third for producing the greatest numbers of billionaires.

With his father having been ranked the world's 68th richest individual, Hugh Grosvenor is joining a very elite club indeed as he takes possession of the Dukedom and his inheritance. It's a club the rest of the world looks at with a mixture of disgust and fascination, but once which makes for some very nice charts nonetheless...