Fig. 1 is taken from an article by Dave Nevell from the April issue of Britain's National Orienteering Magazine CompassSport by courtesy of both author and magazine. Its content is described the following:
The countries have been ranked on how well their overall teams have performed each time round, based on the average gap beteween their runners and the average medal winning times for each discipline. Adjustments have been made for lower numbers of runners (e.g. non-qualification for the final). This then gives an idea of the current world order...The graph is impressing as it visualizes the ongoing and total dominance of the top 4 since the beginning of modern orienteering. Sweden, Norway, Finland and Switzerland took 93.5% of all top four. While these nations all have between 27 and 30 top four positions over the years, former Czechoslovakia -> Czech Rep. got 5, Denmark, Russia and France each got 1.