In 1950 New York with its 12.3 million people was the largest urban agglomeration. It was followed by Tokyo (11.3 mln.), London (8.4 mln.), Paris (6.3 mln.) and Moscow (5.4 mln.).
Only 4 cities from the former top 10 stay there 60 years later. Population of Tokyo more than trippled (reached almost 37 millions in 2010) and now it is the largest urban agglomeration on Earth. Population of New York increased by 8 millions since 1950, and now it is the fouth largest urban agglomeration.
New members in top ten are Delhi and Mexico City with population above 20 millions going after Tokyo. Today seven of ten largest urban agglomerations are located in Asia.