The line graph depicts the proportion of intercontinental congresses in three different cities. Taking all the main trends into account, there were fluctuations in both cities(A and B) and a dramatic increase in city C.
In 1965, City A was the leading host, organizing 35 conferences. However, its prominence declined significantly, with numbers dropping to under 10 by 1975. Although it rebounded to around 25 conferences by 1985 and maintained this level until 2005, its popularity waned again by 2010, falling to just 10 events.
In contrast, City B demonstrated greater stability. Starting with 30 conferences in 1965, it fluctuated only slightly over the decades, reaching its peak of 28 in 1985. By 2010, it experienced a modest decline, concluding with 25 events.
City C began with no conferences in 1965 but saw remarkable growth over the next three decades, reaching 27 events by 1995. From this point onward, the number of congresses it hosted fluctuated slightly, stabilizing at around 25 by 2010.