From the the Insights section of More features menu in User Hub, you can see a graph of meetings you hosted recently and the number of participants in those meetings.

The Insights page has two graphs:

• Meetings I hosted—Shows how many meetings you've hosted, including total minutes spent in those meetings. It also includes the weekly average for the number of meetings and their durations.

  Click the drop-down arrow above the graph to change the timeframe for the graph.

• Participants in meetings I hosted—Shows how many participants were in your meetings, average number of participants, and meetings with the most and fewest participants.

  Click the drop-down arrow above the graph to change the timeframe for the graph.