Bedford/Lawrence County has pretty much been stagnant from a population standpoint. The local economy had been dependent a lot on the automotive industry and the limestone industry and there have been cutbacks in employment in those areas. They used to have a Ford plant there that has been shut down, while GM still has a presence there. So, as far as employment goes, there is not a lot there to attract new residents. There are quite a few residents in Lawrence County that work in Bloomington/Monroe County and are employed at the several medical facilities that are there, as well as IU. Some residents are also employed at the Crane Naval facility which is not far away. Like with a lot of areas, people are waiting to have children at a much older age, and families are just not quite as big as they used to be, and that reflects on the school populations.
That's my two cents on it which may be off-based, and maybe someone with more knowledge of the situation can give a better explanation for it.