Reports for Exec Management

I need to begin putting together monthly reports for 
executive management (CEO) that show the value that the Information 
Security department is providing to the company. The execs know what we 
do, my senior mgmt feels we need to broadcast the value Infosec provides. 

I know a couple things about exec reports.. keep them short (one page), 
never propose a need without an answer, and huge IDS numbers will scare 
them needlessly. How can I show value without being alarmist? If I say that
we 
successfully blocked over 1.5 million attacks last month they'll have a
heart attack. 

What do ya'll provide to your execs? Its tough to show the value of what you

do when that value consists of potentially making something not happen 
(security incident). 

Thanks, 
Mike