Use TopoJSON instead of GeoJSON

The GeoJSON files contain hundreds or thousands of points, making them potentially quite large. The country with the most complex data and largest file size is Canada which weighs in at 1.3MB. If a few of these countries are plotted on a map then the page size is potentially huge and the cache may cause problems with the database.

TopoJSON files are potentially a lot smaller and more efficient to load and render. Unfortunately leaflet doesn't natively support them but it can be extended to support them. The next issue is in loading the files, maybe this could be done through ajax to keep the data stored in the db lower and the initial page load quicker.