Save and Load XML File

I've a script save and load xml file like this:

 using UnityEngine;
     using System;
     using System.Collections;
     using System.Collections.Generic;
     using System.Xml;
     using System.Xml.Serialization;
     using System.IO;
     using System.Text;
     
     public class _GameSaveLoad : MonoBehaviour
     {
         // An example where the encoding can be found is at
         // http://www.eggheadcafe.com/articles/system.xml.xmlserialization.asp
         // We will just use the KISS method and cheat a little and use
         // the examples from the web page since they are fully described
     
         // This is our local private members
         Rect _Save, _Load, _SaveMSG, _LoadMSG;
         bool _ShouldSave, _ShouldLoad, _SwitchSave, _SwitchLoad;
         string _FileLocation, _FileName;
     
         List<SaveStructure.GameItems> _GameItems;
         GameObject[] bodies;
         string _data = string.Empty;
     
         void Awake()
         {
             _GameItems = new List<SaveStructure.GameItems>();
         }
     
         // When the EGO is instansiated the Start will trigger
         // so we setup our initial values for our local members
         void Start()
         {
             // We setup our rectangles for our messages
             _Save = new Rect(10, 80, 100, 20);
             _Load = new Rect(10, 100, 100, 20);
             _SaveMSG = new Rect(10, 120, 400, 40);
             _LoadMSG = new Rect(10, 140, 400, 40);
     
             // Where we want to save and load to and from
             _FileLocation = Application.dataPath+"/";
             _FileName = "SaveData.xml";
         }
     
         void Update() { }
     
         bool isSaving = false;
         bool isLoading = false;
         void OnGUI()
         {
             //***************************************************
             // Loading The Player...
             // **************************************************       
             if (GUI.Button(_Load, "Load") && !isLoading)
             {
                 try
                 {
                     isLoading = true;
                     GUI.Label(_LoadMSG, "Loading from: " + _FileLocation);
                     LoadXML();
                     Debug.Log("Data loaded");
                 }
                 catch (Exception ex)
                 {
                     Debug.LogError(ex.ToString());
                 }
                 finally
                 {
                     isLoading = false;
                 }
     
             }
     
             //***************************************************
             // Saving The Player...
             // **************************************************   
             if (GUI.Button(_Save, "Save") && !isSaving)
             {
                 try
                 {
                     isSaving = true;
                     GUI.Label(_SaveMSG, "Saving to: " + _FileLocation);
     
                     bodies = FindObjectsOfType(typeof(GameObject)) as GameObject[];
                     _GameItems = new List<SaveStructure.GameItems>();
                     SaveStructure.GameItems itm;
                     foreach (GameObject body in bodies)
                     {
                         itm = new SaveStructure.GameItems();
                         itm.ID = body.name + "_" + body.GetInstanceID();
                         itm.Name = body.name;
                         itm.posx = body.transform.position.x;
                         itm.posy = body.transform.position.y;
                         itm.posz = body.transform.position.z;
                         _GameItems.Add(itm);
                     }
                
                     // Time to creat our XML!
                     _data = SerializeObject(_GameItems);
                    
                     CreateXML();
                     Debug.Log("Data Saved");
                 }
                 catch (Exception ex)
                 {
                     Debug.LogError(ex.ToString());
                 }
                 finally
                 {
                     isSaving = false;
                 }
             }
         }
     
         /* The following metods came from the referenced URL */
         string UTF8ByteArrayToString(byte[] characters)
         {
             UTF8Encoding encoding = new UTF8Encoding();
             string constructedString = encoding.GetString(characters);
             return (constructedString);
         }
     
         byte[] StringToUTF8ByteArray(string pXmlString)
         {
             UTF8Encoding encoding = new UTF8Encoding();
             byte[] byteArray = encoding.GetBytes(pXmlString);
             return byteArray;
         }
     
         // Here we serialize our UserData object of myData
         string SerializeObject(object pObject)
         {
             string XmlizedString = null;
             MemoryStream memoryStream = new MemoryStream();
             XmlSerializer xs = new XmlSerializer(typeof(List<SaveStructure.GameItems>));
             XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8);
             xs.Serialize(xmlTextWriter, pObject);
             memoryStream = (MemoryStream)xmlTextWriter.BaseStream;
             XmlizedString = UTF8ByteArrayToString(memoryStream.ToArray());
             return XmlizedString;
         }
     
         // Here we deserialize it back into its original form
         object DeserializeObject(string pXmlizedString)
         {
             XmlSerializer xs = new XmlSerializer(typeof(List<SaveStructure.GameItems>));
             MemoryStream memoryStream = new MemoryStream(StringToUTF8ByteArray(pXmlizedString));
             return xs.Deserialize(memoryStream);
         }
     
         // Finally our save and load methods for the file itself
         void CreateXML()
         {
             StreamWriter writer;
             FileInfo t = new FileInfo(_FileLocation + "/" + _FileName);
             if (!t.Exists)
             {
                 writer = t.CreateText();
             }
             else
             {
                 t.Delete();
                 writer = t.CreateText();
             }
             writer.Write(_data);
             writer.Close();
             Debug.Log("File written.");
         }
     
         void LoadXML()
         {
             if (File.Exists(_FileLocation + "/" + _FileName))
             {
                 StreamReader r = File.OpenText(_FileLocation + "/" + _FileName);
                 string _info = r.ReadToEnd();
                 r.Close();
                 // notice how I use a reference to type (UserData) here, you need this
                 // so that the returned object is converted into the correct type
                 _GameItems = (List<SaveStructure.GameItems>)DeserializeObject(_info);
                 Debug.Log("File Read with item count: " + _GameItems.Count);
             }
             else
             {
                 Debug.Log("Files does not exist: " + _FileLocation + "/" + _FileName);
             }
         }
     }
 

The script above is working correctly. But when I stop the game, then I play the game again, it can't load the last transform position of the game objects. It just load the default position of the game objects. My question is how to save the transform position of the game objects using that script?