So in terms of occupation, are we at more risk or less risk in terms of what we do. And I love spine because every month we learn something new about either occupation or a particular treatment that sort of, it's like doing a jigsaw puzzle and seeing a few more pieces go in but still not getting the whole. And probably the easiest way of putting it is is that couch potatoes and marathon runners don't do well with their backs for all of these things. Those people who are in the middle who exercise maybe three, maybe four days a week, sweat inducing, maybe not even sweat inducing. Maybe all they have to do is go do walking. That those are the patients who do the best and can then cut their risk of back pain or if they do have back pain, maybe actually help improve it. Something where the patient can be a participant in getting him or herself even better. But it would be really, really nice if again, in each individual patient we could know just what was the silver bullet in that particular patient for the back pain. And so we try all these different things to try to get them better.