Yes. We don’t quite understand. It looks like two humps. One the outgoing cohort of physics teachers with another of new teachers coming in. And you might think no-one had been recruited in the meantime. But over the last few years that dip has gotten bigger. We do now have the raw data and the dip drops down to just 12 teachers in the 35-39 age group. We think we should be able to track them all down individually! Then we can ask them if they know what has happened to their peers. In terms of overall numbers it isn’t an insurmountable problem, however for things like curriculum development etc in 10-15 years time it is. The number of really experienced physics teachers in Wales may be just a handful.