It may be meaningless from a standpoint of analyzing workplace safety practices, but from a worker's point of view, 7.7 out of 100 workers per year is the only number that matters.
After all, a worker isn't going to be able to adjust their number of hours worked based on the safety profile of their job. They work the hours they are told, for the entire year, or get fired.
A worker who wants to know their odds of getting hurt needs only know that out of every 100 people with their job, 7.7 will be injured in a year, and that other employers have only half of that.