def get_avg_years_played(self):
        """ Returns the average years played """
        all_players = self._player_manager.get_all()
        for player in all_players:
            number = player.get_player_year_drafted()
            number2 = 2019 - number
            number3 = 0
            number3 = number3 + number2
        avg_years_played = number3/len(all_players)
        return avg_years_played