I don't think there are official statistics on the average of PMP project managers (although PMI has definitely this data). From my experience, the average age of a PMP certified Project Manager is somewhere in the mid 30s.
As for your original case, 23 years is very young to have the necessary experience in project management - the potential of your application getting audited by PMI is very high. I suggest you make sure you have some solid project management experience before applying.