private ObservableCollection <string> CreateYearCollection()
        {
            Year = new ObservableCollection <string>();
            int currentYear = GetLatestRevenueYear();

            //populate year
            for (int i = currentYear; i >= currentYear - 5; i--)
            {
                Year.Add(i.ToString());
            }

            if (DateCollection.Count > 0)
            {
                DateCollection.RemoveAt(0);
            }
            DateCollection.Insert(0, Year);

            return(Year);
        }
        private ObservableCollection <string> CreateMonthCollection()
        {
            Month = new ObservableCollection <string>();
            int loopMonth   = 12;
            int latestMonth = GetLatestRevenueMonth();

            if (SelectedYear == null || (SelectedYear == Convert.ToString(System.DateTime.Now.Year) && latestMonth != 12))
            {
                loopMonth = latestMonth;
            }

            //populate months
            for (int i = 1; i <= loopMonth; i++)
            {
                Month.Add((i < 10 ? "0" + i : Convert.ToString(i)) + AppResources.Month);
            }
            if (DateCollection.Count > 1)
            {
                DateCollection.RemoveAt(1);
            }
            DateCollection.Insert(1, Month);

            return(Month);
        }