Thank you for the detailed clarification. BTW, Abantecart works just fine in IE7 too, so we suggest testing the new releases in IE7 as well, because we heard many users do not have their browsers updated on various reasons, and some just browse with what they happen to have in their old laptop or office/home desktop. This is especially so among Windows users who cannot easily upgrade IE, and also more common in the developing countries.
Global average stats from w3schools.com was interesting, however, we do not know that we believe if that can be representative of the Abantecart's audiences: these stats were built from w3schools.com's website own access log, and w3schools is a website for web-developers, so their stats mainly represent web developers browsers usage.
What we have found, in fact, according to Wikipedia the most common web browser internationally as of November 2013 is actually still Internet Explorer:
http://en.wikipedia.org/wiki/Usage_share_of_web_browsersShipped with windows, IE is often a "choice" of beginner users even though it's the slowest and the least convenient browser we have ever seen!
Anyway, there is a proverb about the stats: "there are lies, big lies and the statistics", so one has to check it for their own website to know for sure.