No reports displayed in index.html of maven>site>index.html

i placed pom.xml as per attachment.
i run mvn test site.
I refresh target folder>check content displayed on clicking index.html.

Issue:
no results are displayed

Refer:
attachment of pom.xml

my code:
========
package com.qtpselenium.framework.datadriven;

import org.testng.annotations.Test;
import org.testng.annotations.BeforeTest;

public class TestNG_test {
@Test
public void f1() {
System.out.println("am using maven for 1st time");
}
@Test
public void f2() {
System.out.println("am using maven for 2nd time");
}
@Test
public void f3() {
System.out.println("am using maven for 3rd time");
}

}