The only reason G-Data does so well in these tests is that its a German product and both the world's leading testers, Andreas Marx, and Andreas Clementi are based in germany. There is some speculation here from many authorities on AV-products from various companies believe that there are some under the table dealings going on here.
Ofcourse, nothing can even be proved. But think about it.. 99.9x% detection. Thats impossible with "gaming". In any case, you are ok with any Tier 1 vendors that have detection rates in the top 10. The 0.xx % points dont mean anything.