Castin67: As I understand it those who didn't play default to a score of 45. They can still play but makes it difficult to qualify.
Colin, every player who is not playing makes it difficult for that Nation to qualify.
Though, the DNF score will affect more those teams where there are few players, because the 45 wil actually be counted if there are less that 10 players with a score (e.g. Belgium).
If there are already 10 scores posted, then having DNF is not as penalizing, though the team loses the chance to improve the overall ranking.
-abq-