Years were established by combining the following:
git log -- assets/logo-256.png
git log -- \
tray/resources/icons/hicolor/scalable/status/syncthing-default.svg
And upstream Syncthing confirms MPL-2.0 is the correct license for
these files for v1.20.1 here:
https://github.com/syncthing/syncthing/issues/8347#issuecomment-1127996095