「Value of type 'UILabel?' has no member 'x'」エラーが解決できません。

Value of type 'UILabel?' has no member 'x'というエラーが出てしまっているのですが、原因がわからないです。
「UILabelという変数にXという値がないよ」ということはわかったのですが、、、

swift
1import UIKit
2
3class Result_ViewController: UIViewController {
4    
5    @IBOutlet var scoreLabel: UILabel!
6    @IBOutlet var messageLabel: UILabel!
7    @IBOutlet var nameLabel: UILabel!
8    @IBOutlet var genderLabel: UILabel!
9
10    override func viewDidLoad() {
11        super.viewDidLoad()
12
13        // Do any additional setup after loading the view.
14         let aD: AppDelegate = UIApplication.shared.delegate as! AppDelegate
15        let score: Int = aD.score * 5
16        scoreLabel.text = "(score)%"
17        
18        if score < 30{
19            messageLabel.text = "二郎禁止レベル"
20        }else if score < 50{
21            messageLabel.text = "プチレベル"
22        }else if score < 70{
23            messageLabel.text = " 小レベル"
24        }else if score < 90{
25            messageLabel.text = "小マシレベル"
26        }else if score < 100{
27            messageLabel.text = "小マシマシレベル"
28        }else if score < 110{
29            messageLabel.text = "大レベル"
30        }else{
31            messageLabel.text = "野猿マシマシレベル"
32        }
33        
34        
35        
36        nameLabel.text = aD.name+"は"
37        genderLabel.text = "ジロリアン" + aD.gender  + "だ!"
38        aD.records.append( ([aD.name, aD.gender, aD.score] as AnyObject) as! [AnyObject] )
39        
40        aD.score = 0;
41    }
42    
43    override func viewDidAppear(_ animated: Bool) {
44        super.viewDidAppear(true)
45        
46        scoreLabel.center = CGPoint(x: scoreLabel.center.x,y: scoreLabel.center.y - 200)
47        UIView.animate(withDuration: 1.0, delay: 0, options: UIView.AnimationOptions.curveLinear, animations: { () -> Void in
48            self.scoreLabel.center = CGPoint(self.scoreLabel.x,self.scoreLabel.y + 200)    }, completion: nil)
49    }
50
51    /*
52    // MARK: - Navigation
53
54    // In a storyboard-based application, you will often want to do a little preparation before navigation
55    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
56        // Get the new view controller using segue.destination.
57        // Pass the selected object to the new view controller.
58    }
59    */
60
61}
62

以下の２行めにエラーが発生しています。

UIView.animate(withDuration: 1.0, delay: 0, options: UIView.AnimationOptions.curveLinear, animations: { () -> Void in
            self.scoreLabel.center = CGPoint(self.scoreLabel.x,self.scoreLabel.y + 200)    }, completion: nil)
    }