When Bug-Buddy starts it will check if it needs to update its configuration files. It does this maximum once per day by checking the time of three XML files on bugzilla.gnome.org.
From the bugzilla.gnome.org webservers logs I grepped the hits to one of these files. Each hit will contain the gnome-vfs version that was used to access it. A pretty safe assumption is that the gnome-vfs version is the same as the GNOME version.
Per GNOME (gnome-vfs) version I now have the number of hits generated during a month of data. Again, Bug-Buddy only checks once a day and the hit is only done when someone starts Bug-buddy (eg app crashes and you click the ‘Inform Developers’ button).