Create persistent Sqlite db in Windows phone 8

Hello Guys I am trying my hands on Windows phone 8 applications and I am stuck into a weird situation here.I am using sqlite in order to create sqlite db and add values into the database.I am able to create the database and add the values in the database successfully but I am having a weird situation here.

Everytime I close the emulator and start the project again the database gets created again which should not be happening because I created the db the very first time I run the application.

Den why it alwaz create it again when I close my emulator and run the project again.If I dont close the emulator the code works fine and db doesnt get created everytime I run the application. Here is my code: Help me out guys.

public string DB_PATH = Path.Combine(Path.Combine(ApplicationData.Current.LocalFolder.Path, "aa.sqlite"));
private SQLiteConnection dtCon;

public MainPage()
{
InitializeComponent();
CreateDatabase();
dtCon = new SQLiteConnection(DB_PATH);
var tp = dtCon.Query<Contacts>("select * from contacts").ToList();
}

private async void CreateDatabase()
{
bool isDatabaseExisting = false;
//Checking if database already exists
try
{
Windows.Storage.StorageFile storagefile = await Windows.Storage.ApplicationData.Current.LocalFolder.GetFileAsync("aa.sqlite");
isDatabaseExisting = true;
}
catch
{
isDatabaseExisting = false;
}
//if not exists then creating database
if (!isDatabaseExisting)
{
String str = System.IO.Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "sqlite.db");
AddDataToDB(DB_PATH);
}
}
private void AddDataToDB(string str)
{
// Create the database connection.   
dtCon = new SQLiteConnection(str);
// Create the table Task, if it doesn't exist.   
dtCon.CreateTable<Contacts>();
Contacts oContacts = new Contacts();
oContacts.Name = "dfgdf";
oContacts.Detail = "asdfsf";
dtCon.Insert(oContacts);
}