Number of people trained

[mihai-sysbio]

Describe the solution you'd like

As a Training Liaison, I want to see the number of people training, so that I can update this number on the ELIXIR Training Platform page.

Describe alternatives you've considered

The only option to do this now is to export the data for the first chart https://tmd.elixir-europe.org/demographic and add the answers. However, adds up to 12.2k+, whereas the "old" number is 38.7k+, so something is not adding up.

Is your feature request related to a problem? Please describe.

Additional context