Какой тип данных вернуть из функции при составлении списка?

public ??????????????? CreditsList(Credit.MainWindow MainWindow)
        {
            Connection();
            string query = "SELECT * FROM credits";
            SqlCommand command = new SqlCommand(query, connection);
            SqlDataReader reader = command.ExecuteReader();
            List<CreditsList> result = new List<CreditsList>();
            while (reader.Read())
            {
                int credit_id = Convert.ToInt32(reader["credit_id"]);
                string credit_name = Convert.ToString(reader["credit_name"]);
                double credit_percent = Convert.ToDouble(reader["credit_percent"]);
                string credit_info = Convert.ToString(reader["credit_info"]);
                result.Add(new CreditsList(credit_id, credit_name, credit_percent, credit_info));
            }
            reader.Close();
            connection.Close();
            return result;
        }