According to the second link I added to my post, It's at least 12 years and three months old. If it was based on
Francz's map (likely, as some of the buildings look identical, and seem identically placed), it's at the most 12 years 4 months and 23 days old. There is a possibility that the map is even older, and Francz partly copied the map, though that seems unlikely to me.