There is not an in-game method of finding this number. The best way I know of is to check the Strava leaderboard here. Alpe du Zwift | Strava Virtual Ride Segment in Temotu Province, Solomon Islands
If you are tracking this for the M-asochist badge (received for climbing ADZ 25 times) There could be some efforts that don’t count because they were done prior to the inclusion of route badges.