The line graph compares the populations of five major cities – Tehran, New York City, Beijing, Moscow and Lagos – from 1970 to the present.
Overall, all five cities experienced population growth over the period, although the pace of increase varied considerably. Lagos and Beijing showed the most dramatic rises, while New York City and Tehran grew more gradually. Beijing became the most populous city by the end of the period.
In 1970, Beijing had the largest population, at around 8 million, followed closely by Moscow with approximately 7 million. New York City and Tehran each recorded about 6 million residents, whereas Lagos had by far the smallest population, at just over 1 million. During the following two decades, populations in all cities increased steadily, with Beijing reaching roughly 11 million by 1990.
However, Beijing experienced a noticeable decline in the mid-1990s, dropping to about 7 million, before rebounding sharply afterwards. From 2000 onwards, its population rose rapidly, peaking at around 22 million at the present time. Lagos also saw rapid growth after 1990, increasing dramatically from around 6 million to nearly 18 million, making it the second most populous city.