User Configuration > Administrative Templates > Microsoft Project 2016 > Project Options > Schedule > Schedule options for Microsoft Project
User
HKCU\software\policies\microsoft\office\16.0\ms project\options\scheduling
Shows resource assignments units as a decimal or percentage. If you enable this setting, resource assignment units will be set to the option you choose from the list. If you disable or do not configure this setting, the user's default setting is used.