Its 
                    vital to see that because we are comparing 8 
                    movements between pairs of aphelion, we are calculating the 
                    1st jump in the image from 1 
                    to 2 (1803 
                    AD to 1959 AD) then the 8th 
                    jump is between orbit 8 
                    and 9 (2954 
                    AD to 3120 AD)
                    
                    The large gray arrow indicates the direction of movement of 
                    the various planetary orbits. Now just compare this image 
                    to the images from the two websites at the top of this page. 
                    We can easily see how large the variation in the aphelion 
                    position is for Neptune. (Just note that you need to rotate 
                    the image around 180 degrees in your mind).
                  But 
                    it is abundantly clear just how vague the concept of an average 
                    is - unless you evolve an 3D-n-body algorithm, 
                    and then display a graph over many thousands of years.
                    
                    Scenario 
                    [60] of OGS15 is a control 
                    test with just Neptune and the Sun. This is because OGS12 
                    demonstrated that large time quanta will cause a recession 
                    to the major axis without any other planets effecting the 
                    orbit. So this scenario is required to show that this inaccuracy 
                    is only -0.0072 
                    as/Ey when unaffected by other planetary gravity. 
                    So Scenario [60] should be compared to Scenario 
                    [28] in this regard as they both operate 
                    at 15000 virtual seconds per iteration.
                    
                    I have not had the processing power to properly run Scenario 
                    [38], which will certainly calculate an error-margin 
                    10x better, taking 10x longer 
                    at 1500 virtual seconds per iteration. If 
                    you have such power (or time), it would be fairly easy to 
                    run Scenario [38] of OGS15 
                    to reveal a more accurate answer to Neptune's apparent recession 
                    to its aphelion and perihelion. I would be interested to know, 
                    and would be able to update my results accordingly. Though 
                    it may take a week or more to properly compute 25 
                    orbits (or more!) of Neptune at this rate, as required.
                    
                    If you do wish to partake in this free study, please contact 
                    me at the Cosmologos 21 
                    forum here: cosmology.africamotion.net