Passing updated array data to uipickerview

Still pretty new to swift, I was having some trouble passing updated data into the pickerview. I'm receiving the "index out of range" error. I have a suspicion that the uipickerview is seeing the empty array, even though the arrays are getting updated. Any help is much appreciated.

import UIKit

class ViewController: UIViewController, UITextFieldDelegate, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var nameDisplay: UILabel!
    @IBOutlet weak var ageDisplay: UILabel!
    @IBOutlet weak var emailDisplay: UILabel!
    @IBOutlet weak var pickerView: UIPickerView!



    @IBOutlet weak var txtfirstName: UITextField!
    @IBOutlet weak var txtAge: UITextField!
    @IBOutlet weak var txtEmail: UITextField!
    @IBOutlet weak var lblValidationMessage: UILabel!

    var ages = [Int]()
    var emailAddresses = [String]()
    var firstNames = [String]()

    override func viewDidLoad() {
        super.viewDidLoad()
        //     lblValidationMessage.isHidden = true
        // Do any additional setup after loading the view.

        //links txtAge to the UITextField class, which gives access to func textfield
        txtAge?.delegate = self
        pickerView?.dataSource = self
        pickerView?.delegate = self
    }

    // restricts the values possible to input in txtAge.text

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

        let allowedCharacters = "1234567890"
        let allowedCharcterSet = CharacterSet(charactersIn: allowedCharacters)
        let typedCharcterSet = CharacterSet(charactersIn: string)
        return allowedCharcterSet.isSuperset(of: typedCharcterSet)
    }

    @IBAction func addUserButton(_ sender: UIButton) {

        //validation of data in the text boxes

        lblValidationMessage.isHidden = true
        if let firstName = txtfirstName.text, firstName == "" {
            lblValidationMessage.isHidden = false
            lblValidationMessage.text = "Enter Your Name"
            return
        }

        if let age = txtAge.text, age == "" {
            lblValidationMessage.isHidden = false
            lblValidationMessage.text = "Please enter a numerical age"
            return
        }

        if let email = txtEmail.text, email.isEmpty {
            lblValidationMessage.isHidden = false
            lblValidationMessage.text = "Please enter an email address"
            return
        }


        //MARK: Adds entries to the 3 arrays

        firstNames.append(txtfirstName.text!)

        //Converts string to int, the age array requires INT
        let age:Int! = Int(txtAge.text!)
        ages.append(age)

        emailAddresses.append(txtEmail.text!)



        txtfirstName.text = ""
        txtAge.text = ""
        txtEmail.text = ""

        //Brings focus back to First Name text field
        txtfirstName.becomeFirstResponder()
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return firstNames.count
    }

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        nameDisplay.text = firstNames[row]
    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return firstNames[row]
    }

}