AngularJS - Model Data Aggregation

I'm using AngularJS and I'm trying to get the minimum and maximum values out of a JSON object.

I have a service which calls an API and returns the JSON object:

angular.module('modelLookupServices', ['ngResource']).
    factory('Year', function($resource) {
        return $resource('/api/years.json/', {},
            {
                query: {method:'GET', isArray:true}
            }
        );
    });

And in my controller I'm calling this service and using it for different things:

function BrowseCtrl($scope, Year) {

    $scope.years = Year.query();

    // I want to get the minimum and maximum years out of my model

}

It's fairly simple to implement a min/max function, but my question is where to do it? Should I do it as a service that I can pass the model to and it should return an object with the min/max values? Or should I put it in the controller as a utility function? Or should it be in a completely different place?

I'm trying to follow AngularJS way of clean code and have an implementation with separation of concerns in mind.