Basic calculations to get 15th city point (13,969,831,458 resources);
14 cities each producing 580 resources per hour.
14*580=8,120 per hour
8120*24=194,880 per day
194,880*365=71,131,200 per year
13,969,831,458/71,131,200=196.4 years to gather resources.
WOW! I am going to have to play for a long time!