Stats collected, in no particular order;
149 - # of ballots cast in GNOME Board of Directors Elections 2015 - source: https://mail.gnome.org/archives/foundation-announce/2015-June/msg00001.html
255 - # of Foundation members as at 22 May 2016 - source: https://www.gnome.org/foundation/membership/
39 - # of languages (with at least 80% of strings translated) supported by GNOME 3.18 - source: https://help.gnome.org/misc/release-notes/3.18/i18n.html.en
25,112 - # of changed incorporated in GNOME 3.18 - source: https://help.gnome.org/misc/release-notes/3.18/
772 - # of contributors to GNOME 3.18 - source: https://help.gnome.org/misc/release-notes/3.18/
24 - # of GNOME GSoC students in 2015 - source: https://wiki.gnome.org/Engagement/AnnualReport/2015/Outreach
4 - # of GNOME Outreachy interns in 2015 - source: https://wiki.gnome.org/Engagement/AnnualReport/2015/Outreach
300 - # of participants who attended GNOME.Asia Summit 2015 - source: https://www.gnome.org/news/2015/05/gnome-asia-summit-2015-concludes/
157 - # of participants who attended GUADEC 2015 - source: https://wiki.gnome.org/GUADEC/HowTo/EstimateAttendees