Two growing seasons later, a picture from early 99, now the plant looks more sparse and out of shape. Partly the reason is that I try to remove all old needles during the winter.
The best method is to pull out the needles one by one, not in pairs. That way, many of the minute, resting buds that are located in between the needle pairs are saved and can be induced to grow in the future and create new twigs.
In the fastest growing areas, I also pull some of this years needles to balance the strength of the plant and to ensure that light and air can reach the inner area of the plant.