The Odoo translations for Odoo V9 have been published on Transifex. Unlike all older versions you will have to translate everything on Transifex. You can start translating here. 
As of today the top three languages are Dutch, Chinese and Portuguese.
1) Dutch: 59% translated,18% reviewed.
2) Chinese: 56% translated, 0% reviewed.
3) Portuguese: 56% translated, 0% reviewed.

Start helping with those translations! The faster they're done the better the Odoo experience.
Yenthe