Garageband keeps reinstalling sound library for every new user - how do i stop this? or centralise the sound library?

Hi

I work in a school and our music department uses garageband and logic to create arrangements for coursework.

Recently they complained that the sound library was limited so we used the Download All Available Sounds option from the menu. We have multiple users setup so students are able to keep their work to themselves, now everytime a new user logs on and runs garageband it wants to install the entire sound library again. You can download it for the user logged on but when the next one logs on it starts all over again.

How can I stop this from happening - surely once the sounds are downloaded they are downloaded to a central area on the Mac and not the users profile!

Specs of all the Macs we have are:

Garageband version: 10.2.0

MacOs: Sierra 10.12

iMac 21.5 inch late 2015 model

1.6Ghz i5

8GB Mem

I can't wipe the Macs and start again as students work are saved on them so stuck now! Otherwise I would and leave it as a single user sign on.

Any one else had a problem like this or know how to fix this I would greatly appreciate any advice. We have tried the usual wipe Garageband and reinstall using an app remover and manually but didn't change anything. Also tried manually copying the files across in the library location where they are stored from another Mac.