Kathryn Huberty -- Morgan Stanley & Co. -- Analyst
Thank you. Good afternoon. Services growth did decelerate from the growth rates in recent quarters. So, can you talk about the factors that played into that slower growth? And then appreciate the new disclosure around paid subscribers. But if you compare what you added in 2018 versus what you expect to add over the next two years, that implies a slowdown in annual net new subscribers. So, should we be thinking about services as a lower growth segment than what you experienced in 2018? And then I have a follow-up.
Luca Maestri -- Apple, Inc. -- Chief Financial Officer
Yes, Katie. Let me take that one. First of all, when we talk about the services business, it's very important to start from the momentum that we have. As you know, we have set an ambitious target for ourselves to double the size of our business from fiscal '16 to 2020 which implied at the time a 19% Kaiger. So far, we've been able to grow above 20%. In fiscal '18, we grew 22%. So, we are on track to achieve our objective. And it's important to understand what is driving the growth of the business. First of all, it's our install base. As we just told you, the install base continues to grow very nicely. It has reached 1.4 billion active devices at the end of December. And really, very little of our services revenue is driven by what we sold in the last 90 days. The second factor for the growth of the services business is that within this installed base, the percentage of users who are paying for at least one service is growing very strongly. This is due to several factors.
First of all, we're offering more and more services. During the last few years, as you know, we've launched Apple Music, Apple Pay, an advertising service for our developers on the app store. All these businesses are growing very strongly. Second, we are making it easier for our customers to transact on our digital stores. We accept many more payment methods today which are very common in certain countries around the world. We've also increased the distribution coverage for many of these services. We're bringing Apple Care to more points of sale around the world. We are launching Apple Pay in more and more markets. And so on. Thirdly, as you mention, our subscriptions are becoming a very large portion of our business. And they are growing very well above services average. The fact that we are saying that we will surpass half a billion during 2020 -- we're not putting a specific date during 2020.
But I think you've seen over recent quarters that we've been adding about $120 million on a year-over-year basis for a number of quarters now. And this is an incredible, staggering number when you think about it. We're also broadening the scope of many of these services. If you take Apple Pay as an example, it started off as the most convenient, most private, and most secure way to make a payment in a store or in an app. Then we took Apple Pay to Safari. Then we started a peer-to-peer service. And we're launching it in new markets across the world every quarter. So, we are broadening that scope. And of course, similar to what we've done in the past, in the last three years, we launched several new services. We're also looking to launch new services going forward that we believe will provide great value to our users. And we're really very excited about the opportunities that we see in front of us. I think you're referring to the deceleration in the growth rate that we've seen in the December quarter.
And I think you're referring back to the growth that we reported in September. I think an important point I need to make -- and I think it's helpful that you asked the question -- is that a portion of this deceleration is truly just a reclassification of the amortization of free services that we've made in connection with the adoption of the new revenue recognition standard. And as we explained 90 days ago, this amortization of free services in the past was reported under products. And now, it gets reported under services. The reclassification is actually diluted to our growth rate because the amortization of free services is a relatively stable number which gets applied to a growing base. So, this reclassification reduces our growth rate versus the previous classification. This factor, by itself, represents roughly one-third of the deceleration that you've seen. We talked about 27% growth in the September quarter. With the reclassification, the growth rate was about 24.5%.
So, that explains about a third of that deceleration. There are, I would say, three factors that explain this difference between the 24.5% to the 19%. The first one is that foreign exchange plays a role. Roughly 60% of our services business is outside the United States. And as you know, the US dollar has appreciated in recent months. And in general, we tend not to reprise our services for foreign exchange on a very frequent basis. The second factor is a well-known issue around the app store in China. The app store in China is a large business for us. We believe this issue around the approval of new-gain titles is temporary in nature but clearly is affecting our business right now.
And then thirdly, we have seen some level of deceleration in Apple Care which has had very, very strong growth during fiscal '18 where we're starting to lap some of the increase in distribution coverage that we put in place recently and the channel field of Apple components that happened when we increased the distribution coverage. But in general, we're very, very pleased with 90% growth. And we think that the business will continue to grow nicely going forward.