Wolfram Alpha Fail
Should it be very easy to handle queries like this?
1) "number of people in the world with an income per capita greater than $12000."
2) "income distribution of the world"
1) "number of people in the world with an income per capita greater than $12000."
2) "income distribution of the world"
Also, this is a terrible way to compare wealths of people. $12000 in Canada will buy you 6000 loaves of bread. In some countries, it might buy you 6000000 loaves of bread. (Numbers are made up, but you get the idea.)
Chucking in your terms and it clearly seems to work out what your question means, and they say it doesn't have enough data on world incomes 2009. Kind of hard to bitch about that.