XAML databinding fejler. ObservableCollection

Jeg har forsøgt at lave en databinding mellem en list<> og en ItemsControl




public class Year {

    public Year() {
      MonthList = new MonthList();
    }

    public Guid CustomerId { get; set; }
    public MonthList MonthList { get; set; }
    public double Average {
      get {
        double avg = 0;
        foreach( Month month in MonthList )
          avg += month.Price;
        return avg/12;
      }
    }

  }



itemsControl.ItemsSource = year.MonthList;


    <ItemsControl x:Name="itemsControl" >
      <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
          <StackPanel Orientation="Horizontal" Background="Transparent"/>
        </ItemsPanelTemplate>
      </ItemsControl.ItemsPanel>
      <ItemsControl.ItemTemplate>
        <DataTemplate>
          <Controls:MonthView ></Controls:MonthView>
        </DataTemplate>
      </ItemsControl.ItemTemplate>
    </ItemsControl>

Emnerne i listen bliver listet ok men når jeg ændre dem opdateres min property ikke



Her er den type der listes

  public class MonthList : ObservableCollection<Month> {
    public MonthList():base() {
    }

  }


  public class Month:INotifyPropertyChanged {

    public enum Months {
      Jan,
      Feb,
      Mar,
      Apr,
      Maj,
      Jun,
      Jul,
      Aug,
      Sep,
      Oct,
      Nov,
      Dec
    }

    public Month(Months month) {
      Name = month;
      Price = 0.43;
    }
    Months _months;
    public Months Name { get { return _months; }
      set { _months = value;
      NotifyPropertyChanged( "Name" );
      }
    }

    double _price;
    public double Price {
      get{ return _price;}
      set {
        _price = value;
        NotifyPropertyChanged( "Price" );
      }
    }

    private void NotifyPropertyChanged(String info) {
      if( PropertyChanged != null ) {
        PropertyChanged( this, new PropertyChangedEventArgs( info ) );
      }
    }
    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    #endregion
  }