Why is it starting numbering from 3, for the threadgroup example?

public class MyThread extends Thread{

    public static volatile AtomicInteger priority = new AtomicInteger(1);

    public synchronized void correctPriority(){
        int newPriority = priority.getAndIncrement();
        newPriority = getThreadGroup() != null && newPriority > getThreadGroup().getMaxPriority() ? getThreadGroup().getMaxPriority() : newPriority;
        setPriority(newPriority);
        if(priority.intValue() > MAX_PRIORITY){
            priority.set(1);
        }
    }

    public MyThread() {
        super();
        correctPriority();
    }

public class Solution {

    public static void main(String[] args) {

        for (int i = 0; i < 12; i++) {
            System.out.print(new MyThread().getPriority() + " ");
        }
        // Output
        // 1 2 3 4 5 6 7 8 9 10 1 2

        System.out.println();
        ThreadGroup group = new ThreadGroup("someName");
        group.setMaxPriority(7);
        for (int i = 0; i < 12; i++) {
            System.out.print(new MyThread(group, "name" + i).getPriority() + " ");
        }
        // Output
        // 3 4 5 6 7 7 7 7 1 2 3 4
    }
}