Maintaining master data in future versions of applications

I am currently creating an application that requires a large amount of user-generated information to be stored in Core Data. When I release a new update of this application, I want to make sure that these users do not lose all this data.

When I delete my current version from my iPhone, all the basic data disappears - this will happen when I create a new version for the update. Is the update of all master data updated when replacing the application? If so, what do I need to do to save the data?

I will not change the master data model between updates if this changes something ...