"Since 1950, the median age, which marks the point at which half the global population is older and half is younger, has risen from 24 to 28. The United Nations expects that by 2050, half of all people in developed countries like Britain will be over 40.One in every 14 people in the world today is over 65 but by the middle of the century it is likely that one in six of us will be." (Quoted from article)