Don't give up!
One of the things I was specifically told by more than one IDC officer upon selection was that "persistence pays off". Also, take what you have learned from the non-select — particularly some of the things
posted earlier in this thread — and improve your package. You can't control your competition, so focus on what you can control. In improving your package, you will also improve yourself.
One note about reapplying: the board does want to see a significant change. Examples of such change could be starting (or finishing) a graduate program, additional interview(s), new volunteer/civic/community experience, additional leadership roles, or taking initiative in other areas. Another example might simply be better characterizing the experience you do have to better align yourself with the things the board is looking for.
The process also requires more than six months to have elapsed since the last board. If fewer than six months have elapsed, a reconsideration letter also must be submitted with your package, which is a brief letter explaining what has improved in your package and why you would like to be considered again.
Of course all of this depends on having a recruiter willing to work with you. As long as you have a recruiter who believes you a worthwhile candidate and is willing to submit your package, you are in good shape. Don't give up!