Geography of women

From 15 to 20, women are like Africa - Part virgin and part explored.
From 21 to 35, women are like Asia - Hot and exotic.
From 35 to 45, they are like the United States - Fully explored and free
               with their resources.
From 45 to 55, they are like Europe - Exhausted, but still interesting
               in places.
From 55 on, they are like Australia - Everybody knows it's down there
               but nobody cares very much.