If I remember this correctly, that age group had so few cases that the error bars essentially covered most of the entire possible range. So even if you have a v

If I remember this correctly, that age group had so few cases that the error bars essentially covered most of the entire possible range. So even if you have a value like 6.3% this might actually be something like 6.3% +- 60%. And it that case the single value is extremely misleading, the true result is "we don't know". I'm not sure I'm remembering the right case here, this happened more than once e.g. with some data from South Africa where low values were quotes without explaining that the studies simply were not large enough to get useful numbers for these subgroups.