The planet has 6.157 billion people, of whom, 4.5% are in the US, and 1% in
the UK.

• 30% of the world’s population is less than 15 years old, but in the
  US this is 21% and 19% in the UK.
• The world’s birth rate of 21 per 1,000 people is higher than the US
  rate of 14 and the UK’s 12.
• 7% of the world’s population is at least 65 years old, compared
  to
• 13% in the US and 16% in the UK
• Life expectancy at birth is 64 years, compared to 77 in the US and 78 in
  the UK.
• Of the 407 million internet users, 36% are in the US and 5% are in the UK.
  (Don’t forget, the US has c.250 m people, compared to 64m in the
  UK.)

Source: Simon Briscoe, The Financial Times, 27/7/02