On the events page, each event shows the number of attendees.
When you click on this, it takes you to a list of event attendees.

On the upcoming events page, the event card also shows the number of attendees. However, the link is to that of the attendees of the first event and this link is the same for all events.

You can see it on the es2 demo site as well.
1st event is Christmas party 2016. The link to attendees is http://es2.stackideas.com/events/3-christmas-party-2016
2nd event is Natale a Roma. The link to attendees is http://es2.stackideas.com/events/3-christmas-party-2016
1st event is New Year. The link to attendees is http://es2.stackideas.com/events/3-christmas-party-2016