Have you followed that up at all? I'd be interested in why departments or agencies.... I see these different graphs, and you can't just imagine that it's because of an increased workload that they have to bring a person with a specialized qualification in for a duration of a year—or more than a year, in some cases. There must be something else at play.
Have you done any individual case studies, pulling out these individuals and trying to learn the story as to what's going on?