Level 10: 5001 - 6000
Level 11: 6001 - 7000
Level 12: 7001 - 8000
Level 13: 8001 - 9000
Level 14: 9001 - 10000
Level 15: 10001 +
The pages describing this have yet to be updated:
http://www.element14.com/community/docs/DOC-37508/l/what-is-my-element14-profile
http://www.element14.com/community/community/experts/your-ranking
the first page also has a typo just after the table:
"Find out more about you ranking levels"
^
Edited to add: first link has been replaced with:
