The graphic shows a sharp drop in the year 2002 in contrast with the increasing trend in the dollar value of Aol's advertising revenue over the period from the year 1998 to the year 2001. 
The dollar value of Aol's advertising revenue reaches to 2.27 billion dollars in the year 2001 and drops to 1.14 billion dollars in the year 2002. 
The dollar value of this revenue in the year 2002 is nearly 2.2 times higher than that in the year 1998.