And it's interesting to note that that's almost twice as many iPhones as we'd sold in a comparable period of time, and over seven times as many iPods as we had sold in the period of time. And so I think it's important to kind of put that in perspective. We've come a long way very very quickly.
Looking at it by market a bit, which I think is important; I think Luca mentioned a little bit of this in his comments, in the education market in the U.S. we have a 95% share. And so the focus in education is on penetration, is in getting more schools to buy. And my belief is the match has been lit, and it's very clear to the educators that have studied this that student achievement is higher with iPad in the classroom than without it. And so I'm confident we've got a really great start in education, far beyond the U.S. now; this is happening in many, many parts of the world.
In the enterprise market, we're seeing virtually all--98%--of the Fortune 500s that are using iPad, and we're seeing, according to the latest data we have, that 91% of the activations of tablets in enterprise were iPad. And so this is also an astonishing number, and many of those enterprises are writing apps that are key proprietary apps for running that business. And this is great for that company because they're more productive as a result of that.
And so once again, our--just like in education in a way, what we have to do in enterprise is focus on penetration. It has to be deeper, and broader, but in terms of having people begin the process, begin writing apps, we're doing a pretty good job of that.
In the retail market, if you look at the U.S. as a proxy--the NPD numbers from March just came out a few days ago, and we had 46% share. And, embedded in that 46 [percent], there's a lot of things in there that I personally wouldn't put in the same category as iPad, and that are weighing the share down. It's certainly a market we wouldn't play in, and a type of product you would never see an Apple brand on. So we feel like we're doing well, there.
Office [for iPad], I believe, does help. It's very unclear to say how much; I believe that if it would have been done earlier, it would have been even better for Microsoft, frankly. There's lots of alternatives out there from a productivity point of view: some of which we brought to the market, some of which many, many innovative companies have brought. But I do see that Office is still a very key franchise in the enterprise, in particular, and I think having it on iPad is good. And I whole-heartedly welcome Microsoft to the App Store to sell Office. Our customers are clearly responding in a good way that it's available. But I do think it helps us particularly in the enterprise area.