In general

In general, over the sixty years surveyed, there has been an increased volume of population in all four countries with Americans always registering the highest figures.
Upon giving the table a more detailed analysis, it can be clearly seen that the USA has by far been the most densely populated place. In 1990, there were 249.9 million Americans living in the region, about 70 times greater than 3.4 million people in New Zealand which was the most sparsely populated area of all. After a decade, its population increased by around 25 million to 275.1 million while in New Zealand only 3.8 million inhabitants were recorded. The USA is expected to remain the most populous country of all as in 2020, 320.6 million people will reside in the area and by 2050, its population will have reached 349 million, almost 75 times larger than the volume of New Zealanders, at 4.7 million