private void LoadHighscores()
{
uscEasy.gridHighscore.ItemsSource = Highscore.AllByDifficulty(Difficulty.Easy);
uscMedium.gridHighscore.ItemsSource = Highscore.AllByDifficulty(Difficulty.Medium);
uscHard.gridHighscore.ItemsSource = Highscore.AllByDifficulty(Difficulty.Hard);
}