Click for the interactive map for the graphic above.
The graphs above show the very rapid growth of the world population. The is largely due to vast improvements in public health care and sanitation.
Fortunately economic improvements lead to reduced birth rates. The world population growth has been very rapid. It slows, though, as countries become more affluent - people marry later, space their kids, start having children later, and have fewer children. And affluence leads to better birth control. And retirement plans replace children to take care of parents when they get older.
The graphic below shows population density by country.