Android's market share dominance continues.

Demand for Android smartphones propelled the mobile operating system of Alphabet's (NASDAQ:GOOG) (NASDAQ:GOOGL) Google in the first quarter, as it captured a larger share of the smartphone market. In the U.S., Europe, and China, more buyers chose Android smartphones in the first quarter, according to Kantar Worldpanel's latest data. Meanwhile, Apple's (NASDAQ:AAPL) share of the smartphone market declined.

Android phones have been outselling Apple's iPhone for many years, and historically, Apple's share of the smartphone market trends down in the first quarter, as the current crop of iPhones begin to show their age and Google's hardware partners unveil a new round of flagships. But Kantar's latest report is notable, as it signifies a larger loss than in previous years.

A strong first quarter for Android

Kantar Worldpanel tracks smartphone sales in many major markets and discloses market share data regularly. Here's how Android and iOS have performed in the first quarter going back to 2012.

U.S. 2016 2015 2014 2013 2012 Android Market Share 65.5% 58.1% 57.9% 49.3% 48% iOS Market Share 31.6% 36.5% 36.7% 43.7% 44.6% China 2016 2015 2014 2013 2012 Android Market Share 77.7% 71.5% 80% 71.9% N/A iOS Market Share 21.1% 26.5% 17.9% 23.3% N/A U.K. 2016 2015 2014 2013 2012 Android Market Share 58.8% 52.9% 57.7% 58.4% 49.3% iOS Market Share 34.8% 38.1% 30% 28.7% 30.1% Germany 2016 2015 2014 2013 2012 Android Market Share 76.1% 71.3% 77% 73.6% 63.4% iOS Market Share 17.8% 18.3% 15.3% 16.9% 18.7% Spain 2016 2015 2014 2013 2012 Android Market Share 92.9% 89.9% 89% 93.7% 76.8% iOS Market Share 6.40% 7.00% 7.20% 3.10% 5.40% Italy 2016 2015 2014 2013 2012 Android Market Share 78.3% 66.2% 70.7% 62.5% 48.4% iOS Market Share 14.8% 17.5% 12.9% 19.9% 22.6% France 2016 2015 2014 2013 2012 Android Market Share 74.3% 64.6% 65.2% 63.3% 57.8% iOS Market Share 20% 19.4% 23.4% 21.2% 20.5%

In the U.S., the U.K., Italy, and France, Android had its strongest first quarter on record. In other markets, Android's strength was noticeable, edging back after last year's decline. The release of the iPhone 6 and iPhone 6 Plus, the first larger-screen phones from the Cupertino tech giant, propelled iOS's share of the smartphone market in China, the U.K., Germany, and Italy in the first quarter of 2015. That strength receded somewhat this year.

Some of Android's gain was driven by the decline of alternative operating systems. For the last five years, Android and iOS have held the smartphone market in a virtual duopoly, even though Windows Phone and BlackBerry have captured some sales. Increasingly, though, that's no longer the case. In the first quarter of 2015, Windows Phone captured 14.4% of the Italian smartphone market, for example. But in the first quarter of this year, that number fell to just 6.3%.

Android strength wasn't driven by any particular vendor. Samsung's flagship Galaxy S7 went on sale in the first quarter and managed to exceed the Korean tech giant's expectations. Kantar noted that it played a role in driving Android's strength among American buyers, but it didn't have much of an effect in other markets. Europeans and Chinese consumers opted for devices from Huawei, ASUS, Wiko, and Oppo in increasingly greater numbers.

The iPhone remains Apple's most important segment

The iPhone generated nearly 65% of Apple's revenue last quarter, and likely a larger percentage of its net income. Any changes in the relative popularity of the iPhone have a significant effect on Apple's financials.

Apple shares have performed poorly this year, falling more than 4% as the iPhone business has stalled. iPhone unit sales contracted 16% on an annual basis last quarter, and revenue fell 18%. That was much worse than the larger smartphone market, which saw a modest 0.2% gain in shipments, according to IDC. In the quarter before that, Apple saw no iPhone unit growth at all, and its revenue inched up a paltry 1%.

In this slower-growth environment, Android vendors appear to be outperforming Apple, which hopes to drive interest with this year's iPhone.