When did Ubuntu switch to systemd?

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Tags

1. #systems
2. #since
3. #easily
4. #changed
5. #systemd
6. #packages
7. #running
8. #default
9. #present
10. #installed
11. #march
12. #vivid
13. #switching
14. #upstart
15. #ubuntu
16. #between
17. #switch
18. #before