Well, in that case, maybe this is interesting to you. I ran a user survey last year for my instance and anyone else wanting to answer and one question was age. Here’s the age group graph:
The y-axis is number of respondents, x-axis is age group. Obviously this only applies to the people that responded to the survey and thus might not apply in general to the fediverse, but it’s probably an indication. And, well, it’s mostly smoothly distributed without any major gaps or humps (slight hump at 30-34 but not sure if that’s statistically significant).