public List<Invoice.InvoiceType> GetRouteInvoiceTypes()
{
var types = new List<Invoice.InvoiceType>
{
Invoice.InvoiceType.Tickets,
Invoice.InvoiceType.OnFlightIncome,
Invoice.InvoiceType.Fees,
Invoice.InvoiceType.Maintenances,
Invoice.InvoiceType.FlightExpenses,
Invoice.InvoiceType.Wages,
Invoice.InvoiceType.Total
};
return types;
}