Why is this property not showing in the Properties Box?
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        contacts.Add(new Contact()
        {
            Name = "James",
            Email = "james@mail.com",
            PhoneNumber = "01234 111111"
        });
        contacts.Add(new Contact()
        {
            Name = "Bob",
            Email = "bob@mail.com",
            PhoneNumber = "01234 222222"
        });
        contacts.Add(new Contact()
        {
            Name = "Emma",
            Email = "emma@mail.com",
            PhoneNumber = "01234 333333"
        });
    }

    protected List<Contact>  contacts = new List<Contact>();

    public List<Contact> Contacts
    {
        get { return  contacts; }
        set {  contacts = value; }
    }

}

[Browsable(true)]
public List<Contact> contacts
{
    get { return this._contacts; }
    set { this._contacts = value; }
}
protected List<Contact> _contacts = new List<Contact>();