From memory it was a touch more than 90—and while I never ceased to be amazed by what we achieved with the resources we had, everyone else was expanding while Opera didn't, despite clearly having the money to do so.
When it comes to lacking desktop market share, it's undeniable that has an effect on site compatibility—people kept on supporting IE6 till a few years ago, after all, despite all its flaws. If Opera had more marketshare, it could've afforded to not keep up (though then we'd have articles about how Opera is the new IE!). I think, however, site compatibility was less about marketshare in later years and more about ancient incompatibilities (percentages rounding down, keyboard events, range events, selection, document loading/unloading) that were increasingly important in an increasingly dynamic web. People were deliberately deciding not to support Opera at that point because it involved more than a trivial amount of work because of bugs like those and the lack of marketshare.
