Teleport to a custom spawn

Why does this not work? I will always be teleported to the default spawn

arena.yml:

Code:

spawnx: 110.000000
spawny: 75.000000
spawnz: 92.000000
spawnworld: Taiga
saferadius: 10
maxplayer: 16

code:

PHP:

    public function onRespawn(PlayerRespawnEvent $event)
    {
        $player = $event->getPlayer();
        $arena = new Config($this->getDataFolder() . "/arena.yml", Config::YAML);
        if($player->getLevel()->getFolderName() === $arena->get("spawnworld"))
        {
            $player->setSpawn(new Position($arena->get("spawnx")+0.5, $arena->get("spawny"), $arena->get("spawnz")+0.5, $this->getServer()->getLevelByName($arena->get("spawnworld"))));
        }
    }

You need to set the spawn before the player dies.

ok thanks!