private void RefreshTotalsProperties()
{
var ia = SelectedInvoices.ToArray();
HoursWorked = Analyser.HoursWorked(ia);
OrdersDelivered = Analyser.OrdersDelivered(ia);
DropFees = Analyser.DropFees(ia);
Tips = Analyser.Tips(ia);
Adjustments = Analyser.Adjustments(ia);
TransactionFees = Analyser.TransactionFees(ia);
Total = Analyser.Total(ia);
}