Anyone in a retail nursery care to share what percentage of their plant merchandise is lost to shrinkage?

I've heard there is a standard deduction for shrinkage with IRS but can't find that on the internet. Thought it might give me a bit of an idea what somebody considers "usual".

I'm looking at somewhere around 6%(dollars of dumped/lost plants compared to all plants sold ) in my department and wonder if it's at all in line with what others experience. This would be primarily annuals.

Thanks.