How to add multiple extra spawn levels to go along with the level spawn sequence

This is my code once gamescore 3 is hit a special enemy is spawned but when I try to do the same if state like for 8 I get a error message. I can only add one bonus line for code how can I do multiple.

func startNewLevel(){
levelNumber += 1

    if gameScore == 3 && bonus == false{
        bonus = true
        addbonus()
    
    }
    else{
    if self.actionForKey("spawningEnemies") != nil{
        self.removeActionForKey("spawningEnemies")}
    var levelDuration = NSTimeInterval()
    switch levelNumber{
    case 1: levelDuration = 1.5
    case 2: levelDuration = 1.4
    case 3: levelDuration = 1.4
    case 4: levelDuration = 1.3
    default:
        levelDuration = 0.5
        print("cannot find level info")}
    let spawn = SKAction.runBlock(spawnEnemy)
    let waitToSpawn = SKAction.waitForDuration(levelDuration)
    let spawnSequence = SKAction.sequence([waitToSpawn, spawn])
    let spawnForever = SKAction.repeatActionForever(spawnSequence)
        self.runAction(spawnForever)}}

if gameScore == 10 || gameScore == 3 || gameScore == 8 || gameScore == 44 || gameScore == 50 || gameScore == 100 {
startNewLevel()}

You would have to use else if but really, the best thing to do would be to use switch case statements.