I figure if your area hasn't changed much it'd be a waste of resource to update your area. No local new or closed roads are there ? Any new housing estates ?
Quote:
"How often is the imagery in Google Earth updated?
Google Earth displays the best available imagery, most of which is one to three years old. The information in Google Earth is collected over time and is not in real time."
http://support.google.com/earth/bin/answer.py?hl=en&answer=187961