Store a global variable from ajax call

I have a list of years in an array format [2018, 2019, 2020] that is returned from my back end. Right now, i’m using a setup controller to make the ajax call and set it as a value to be used by my ember-power-select. However, I just need this to be done once, like on application load and have it as a global variable, instead of everytime the controller loads since this array will rarely change.

How should I go about this ?