Is is possible for geo chart to display sub-regions of Malta

[N_M]

I am trying to represent a series of results across Malta by sub-region.

By using the code below the map focuses on Malta ok for me

 var options = {

        region: 'MT',

        };

 However when I try to subdivide by regions within Malta (as below) it seems to pick one of the regions at random and show the value for it for Malta overall - the entire map is also highlighted as if it were that entire sub-region

 function drawRegionsMap() {

        var data = google.visualization.arrayToDataTable([

          ['Region', 'Proportion'],

          ['MT-56', 28.3],

          ['MT-12', 7.6],

          ['MT-60', 2.3],

          

        ]);

Would I be right in thinking the geo-chart function doesn't retain the ability to subdivide somewhere smaller like Malta?

Many thanks