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One possible explanation for this slower rate of retail growth, of course, is the shift towards e-commerce and online retailers. Privately held brick-and-mortar retail companies are facing more competitive pressure than ever from online retail, as well as big box retailers.

"Even Amazon.com is becoming a common grocery store for some consumers," Bierman says.

The list also includes several industries within healthcare, such as Outpatient Care Centers and Medical and Diagnostic Laboratories. Inclusion on the list is far from a death sentence, however, as sales growth only tells part of the story, Bierman says. Without the context of other data, like net profit margin and previous periods' sales percent change, the most recent sales figures can be slightly misleading.

Legal Services is one industry where slow sales growth does not tell the full story, Bierman says. The growth may be slow but it is also consistent, and companies in this sector are much more profitable than the average private company.