If the world were a village of 100 people then:
61 would be from Asia
13 would be from Africa
12 would be from Europe
8 would be from South America, Central America (including Mexico) and the Caribbean
5 would be from Canada and the United States
1 would be from Oceania
It also looks at issues such as food, water, religion, wealth, possessions, living conditions and literacy.
This book is a great resource for exploring cultural diversity. It can also be used to look at all areas of the humanities curriculum economics, history and geography. The book can also be used in maths looking at areas such as percentages, ratios, and statistics and graphing. It can also be a good starting point for areas in science such as looking at the environment and sustainability.
The book would be a good resource to use in grades 3-6 (VELS level 3-4). It could even be used in a secondary school at years 7-9, maybe even higher as it is a fascinating way of looking at the world no matter how old you are.
If you do a Google search you will find this page which will lead to some resources and teaching ideas if you search. There are other pages out there with ideas on how to use the book as well, again you can find them with a Google search.
Here is an interesting image which comes from http://www.miniature-earth.com.