Just wondering if you meant to say "Is this because, monitors for 'Offline Devices' are not included in this number?"
If you want to see how many monitor are offline you can create a new smart group. Create it to include monitors and the filter should be add monitors where status is offline. Then when you are looking at the parent group of where you created the smart group you will see a summary of how many monitors match the offline status.
If you do really only care about monitors that belong to devices that are offline, meaning all the devices monitors are disabled then you can do the same thing. Just create a smart group that contains devices that have status of offline. Then in the parent groups view, in the device tree view under the last results column, you will see it give the total number of members that are disabled. This members total is actually the monitor count and not the device count.
Hope this helps!
Thanks Matt! What I meant to say was that the total number of Enabled Monitors in different groups was lass than what was showing up in 'About'. I wanted to confirm if this was because the offline monitors were not being included in the 'Enabled Monitors' number?
Your suggestion helped in determining the number of monitors that belong to offline devices. Thanks for that.