AACC - Historical Reporting Skillset

[chrde]

Can someone tell me how the historical field "Answer delay" on skillset can be interpreted?

This is my scenario:

1. I send in a new email
2. In the realtime reporting (Skillset Report) I can see the mail waiting for 1 minute 45 seconds
3. I log out all my agents so the skillset gets out of service
4. The standard multimedia script will dequeue the email from the skillset after max 2 minutes
5. Then I login my agent again
6. In the realtime reporting (Skillset Report) I can now see the mail is waiting for 6 minutes
7. After 15 seconds I make my agent available
8. The Agent answers the email

When I check the historical reporting (Skillset Performance) the "answer delay" for this particular skillset is 15 seconds.

So it seems the answer delay is reset every time the skillset gets out of service. How am I supposed to calculate the service level then?