The graph shows the information about international conferences in three capital in 1980-2010.

A glance at the line graph provided illustrated the number of international conferences that were hosted in different cities during the period from 1980 to 2010.
Overall, it is clear that there was a considerable fluctuation in conferences over the period of 30 years. The figure of international conferences in city C changed more significantly than other two cities.
Between the 1980s and the 2000s, city C increased quickly in the number of international conferences and reach a peak of 35 conferences in the 2000s. The latter years of the graph, then, this number declined gradually to over 30 conferences.
While, both city A and city B are similar to the trend of changing international conferences. Within former 25 years, the number of the conferences in these 2 cities went up and down similarly. Until in the middle of the 2005s, there had the same number, about 27 conferences in both 2 cities. After that, there was followed by a period of steady fall with the figures of the conferences of both city A and city B in the final year of the graph.