It´s kind of hacky, but there is an existing stored procedure that fetches entries from shipped orders.

            DataCommand dataCommand = OrderDataHelper.CreateTranDataCommand();
            DataParameters dataParameters = new DataParameters();
            DataSet dataSet = new DataSet();
            string query = "[dbo].[ecf_reporting_ProductBestSellers]";

            dataCommand.CommandText = query;
            dataCommand.CommandType = CommandType.StoredProcedure;
            dataParameters.Add(new DataParameter("ApplicationId", CatalogConfiguration.Instance.ApplicationId, DataParameterType.UniqueIdentifier));
            dataParameters.Add(new DataParameter("interval", "year", DataParameterType.VarChar));
            dataParameters.Add(new DataParameter("startdate", DateTime.Now.Date.AddDays(-100), DataParameterType.VarChar));
            dataParameters.Add(new DataParameter("enddate", DateTime.Now.Date, DataParameterType.VarChar));
            dataCommand.Parameters = dataParameters;
            dataCommand.DataSet = dataSet;

            DataResult dr = DataService.LoadDataSet(dataCommand);
            int[] po = new int[dataSet.Tables[0].Rows.Count];
            foreach (DataRow row in dr.DataSet.Tables[0].Rows)
            {
                int x = (int)Math.Round(decimal.Parse(row["Ordered"].ToString()));
                if (x != 0)
                {
                    Console.WriteLine(row["Code"]);
                    Console.WriteLine(row["Ordered"]);
                }
            }