Each individual version is broken down separately in that chart, so you're looking at the market share for Firefox 49 specifically. The broader number seems to

Each individual version is broken down separately in that chart, so you're looking at the market share for Firefox 49 specifically. The broader number seems to be closer to 11%. Anecdotally, people and organizations that aren't tech-savvy are more likely to use Firefox as well, so it just depends on the target audience.