I have a SKSpritnode table for a background in a game and I want the background to change as the players points reach a certain level eg every 20 points. I use a range operator as shown below. The code below builds and runs but background doesn't change.

func setupTable(){
        if(0...19).contains(playerScore) {
            let table = SKSpriteNode(imageNamed: "ovaloffice")
            addChild(table)
            table.position = CGPoint(x: size.width/2, y: size.height/2)
            table.zPosition = -1}
        else if(20...39).contains(playerScore)  {
            let table = SKSpriteNode(imageNamed: "austin")
            addChild(table)
            table.position = CGPoint(x: size.width/2, y: size.height/2)
            table.zPosition = -1}
        else {
            let table = SKSpriteNode(imageNamed: "bond")
            addChild(table)
            table.position = CGPoint(x: size.width/2, y: size.height/2)
            table.zPosition = -1}
            }

            func addPlayerScore() {

      playerScore += 1
      playerLabel.text = "Arn: \(playerScore)"
  }

  }