SQL for customer tax exemptions

Hello,

We're trying to manager our overall customer tax exemptions better.  One of the things that we've been unable to do is see wholistically for our customer base which of our customers have tax exemptions applied to them.  Specifically, we typically apply our exemptions down to the Account Site level.  We have been unable to find a report or write custom SQL to accomplish this.  We've even created an SR with this question and received no solution.  I'm wondering if anyone else out there has been able to create a SQL that will show customers with tax exemptions down to the Account Site level?