Financial numbers alone offer scant profit improvement insights. For real improvement, you must develop a theory for how to improve service value and/or cost effectiveness and then create and capture new metrics to test your theory. This gives you the data to act on what is working. Amazon, for example, has roughly 500 proprietary metrics: 80% are related to customer value improvement.
However, the National Association of Electrical Distributors (NAED) industry overview PAR report does provide some helpful ratios. Insight into the NAED 2016 PAR report can help you understand how to improve your profit.