Koen de Groot News
Koen de Groot is a Dutch swimmer who won a silver medal in the 50m breaststroke at the European Championships.
Koen de Groot is a Dutch swimmer who won a silver medal in the 50m breaststroke at the European Championships.
Koen de Groot is a Dutch swimmer who won a silver medal in the 50m breaststroke at the European Championships.
Koen de Groot is a Dutch swimmer who won a silver medal in the 50m breaststroke at the European Championships.