为什么权限高的线程运行次数反而少？

Question

package thread;class ThreadA extends Thread {
  boolean threadFlag=true;
  int click;
  ThreadA(String threadName) {
    super(threadName);
    start();
  }
  public void run() {
     while(threadFlag)
      click++;
  }
  public void cancel() {
    threadFlag=false;
  }
}    
public class ThreadWithPriority {
  public static void main(String[] args) {
    Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
    ThreadA t01=new ThreadA("Thread01");
    ThreadA t02=new ThreadA("Thread02");
    ThreadA t03=new ThreadA("Thread03");
    // t01:6  t02:5  t03:4
    t01.setPriority(Thread.NORM_PRIORITY+1);  
    t03.setPriority(Thread.NORM_PRIORITY-1);
    try {
      Thread.sleep(10000);
    }
    catch(InterruptedException e) { System.out.println("Main interrupt."); }
    t01.cancel();
    t02.cancel();
    t03.cancel();
    try {
      t01.join();
      t02.join();
      t03.join();
    }
    catch(Exception e) { System.out.println("Thread Interrupt."); }
    System.out.println(t01.getName()+":"+t01.click);
    System.out.println(t02.getName()+":"+t02.click);
    System.out.println(t03.getName()+":"+t03.click);
  }
}运行结果：
C:\classes\thread>java thread.ThreadWithPriority
Thread01:13994
Thread02:1228687562
Thread03:52494048为什么结果是 t02>t03>>t01？