The graph show the information about international conferences in three capital cities in 1980 2010

The line graph compares the number of worldwide conferences which was hosted by city A, B and C from 1980 to 2010.
Overall, it is clear that the number of international conferences declined in cities A and B while this figure for city C had an upward trend in this period. Besides, after thirty years, city C became the city that hosted the most global conferences in three cities.
In 1980, city A and B organized 35 and 30 global conferences respectively. Although the same trend in the fluctuation of hosting conferences, city A always organized global conferences more than city B until 2005, both two cities hosted the same worldwide conferences, about 27 conferences. By 2010, there were 26 conferences in city B and 24 conferences in city A.
In contrast, no global conferences took place in city C, however, the number of international conferences increased sharply and peaked at the highest point 35 conferences by 2000. Between 2005 and 2010, these figures remained higher than other cities and fell down slightly to approximately 30 conferences.