You probably think this is easy, and it kind of is, but there are some details worth poking at. If you sell a product for $10, that's $10 in gross sales. If the product cost you $8 to make, then you have $2 in net sales. All done, right? Well, mostly. The purpose of collecting data is to drive action. So what action can you take with the data above? Not much, it turns out. Like other measures, sales should should be expressed in terms of your sales strategy.
The problem with measuring safety is that you're actually measuring the absence of something (injury). You can take no measurable action and get lucky by having no workplace injuries, or you can take tons of measurable actions and get tons of injuries. We improve processes by using past patterns to take future action, but "past patterns" in safety means someone got hurt, or worse. So the trick is looking for the patterns that took place before the injury and measuring (and improving) those.