5% of time spent above 75% utilization on routers

Hello,

One of our directors has asked if I can create a report that shows which sites spent more than 5% of their time above the 75% of their circuit utilization mark between 7am CST and 7pm CST M-F on a weekly basis.  I'm having no problems writing a report except for that 5% of time qualifier which I am pretty sure would require some SQL manipulation and my SQL skills are next to nil.  Our DBAs are backed up with a bunch of project work so I am getting nowhere fast there.  Has anyone tried to create this and been successful?

Any assistance is greatly appreciated.

Thanks.