Пытаюсь получить скалярное значение AVG из фокспрошной таблицы. Выдает ошибку OLEDBExeption. Причем с командами SUM, COUNT, MIN, MAX работает нормально.

Private Function ReadAvg()
Dim ConnectionString As String = "Provider=VFPOLEDB; Data Source=" & DataBasePath
Dim QuiryAVG As String = "SELECT AVG(MicexInd) FROM NewIndex"
Dim ReturnValue As Double
Using connection As New OleDbConnection(ConnectionString)
Dim command As New OleDbCommand(QuiryAVG, connection)
connection.Open()
Dim avg As Double = command.ExecuteScalar
ReturnValue = Math.Round(avg, 2)
End Using
Return ReturnValue
End Function