Independent market analysis firm Kantar Worldpanel has published its latest monthly data for sales in several key smartphone markets around the world, including the US, China, and the EU5 - the top five European Union markets of Great Britain, Germany, France, Italy and Spain.

The latest data, for the three months ending in December 2016, shows considerable growth for iOS in many of these key markets, although strong competition from Android in China continues to pose challenges for Apple devices there. Android grew in numerous markets - and by a sizeable amount in some countries - but unsurprisingly, Windows' share of smartphone sales continued to drop around the world.

Let's take a closer look at the latest Kantar data for some of those key markets.

Android sales market share dropped significantly year-over-year (YoY) in the United States, falling from 59.1% in the three months ending in December 2015, down to 54.4% a year later. The big winner there was iOS, which increased its share by 5.3 percentage points (pp), rising to 44.4% of sales.

"iPhone 7 and iPhone 7 Plus were the top sellers for the holiday period, netting their highest share since their release in mid-September, and representing 28% of smartphones sold in the fourth quarter," Kantar's Lauren Guenveur explained. "Despite the expected fallout from Samsung’s problems with the Galaxy Note 7, the company maintained a share of 28.5%, down only 0.9% from one year earlier. Samsung’s Galaxy S7 flagship device, announced at Mobile World Congress 2016, was the third best-selling phone in the fourth quarter."

Windows phone sales halved YoY from 1.6% to just 0.8%, as Microsoft's Lumia range approached the end of its retail life, with few alternative Windows 10 Mobile devices to choose from among the company's hardware partners.

Windows suffered a far more devastating YoY loss in Great Britain, one of the mobile platform's more successful markets, where its sales market share collapsed from 9.2% to 1.7%. But Microsoft's loss proved to be Apple's gain, as iPhone sales share soared by a whopping 9pp, rising from 38.6% to 47.6% YoY (although it dipped slightly compared with last month, when it was at 48.3%).

"Apple achieved its highest loyalty ever in Britain, with 96% of those Apple owners who replaced their phones buying another iPhone," said Dominic Sunnebo, Business Unit Director for Kantar Worldpanel ComTech Europe. "More than 50% of iPhone 7 buyers were upgrading from iPhone 6 as the brand’s lifecycle continues to hover around 24 months."

Apple and top Android vendor Samsung together accounted for 73% of British smartphone sales during the quarter. Android saw a slight YoY decline, as other manufacturers saw the popularity of their devices rise and fall. "Brands like OnePlus, Alcatel, and Google experienced an increase from the prior year, while big names like Sony, LG, and HTC declined," Sunnebo explained.

In France, Android sales share rose by a healthy 2.3pp YoY, up from 69.9% to 72.2%, but iPhone sales increased by a greater proportion of 3.9pp, growing to 24.4%. Windows sales market share dropped from 8.7% to 3.3% during the same period.

Germany was one of the few markets where Windows phone sales reached double-digit market share - but those days are long gone. Its share now stands at 2.5%, falling from 6.4% YoY.

Android strengthened its commanding lead in Germany, growing from 72.6% to 75.6%, while iOS saw modest YoY growth of 1.4pp, up to 21.6%.

Android's domination of the Spanish smartphone market remains unassailable for now, growing to a remarkable 87.2% share. iOS held its ground at just over 12%, but Windows' sales market share fell by two-thirds YoY, decreasing to just 0.5%.

Over in Brazil, Android's share is even more astonishing. During the fourth quarter of 2015, its sales market share was 91.8%; it rose by a further 1.9pp to an incredible 93.7% by the end of 2016.

While Windows' share fell from 5.1% to 1.9%, iOS rose from 2.8% to 4.1% YoY.

In China, Android surged in popularity, growing its sales market share by 9.3pp YoY, increasing to 80.7%. Much of that growth came at the expense of iOS, which plummeted from 27.1% to 19.1% by the end of 2016.

"iPhone 7 remained the top-selling model in the Chinese market in the last quarter of 2016 at 6.8%. However, its share was smaller than last year’s iPhone 6s, which represented 10.5% of sales in the fourth quarter of 2015," Tamsin Timpson, strategic insight director at Kantar Worldpanel ComTech Asia, explained. "Looking at the broader market, there was a shift in popularity. The Top 10 list of smartphone models sold in Urban China in 2015 consisted of just three manufacturers Apple, Huawei, and Xiaomi. In 2016, a fourth vendor was added to that list – Oppo."

Windows smartphone sales have never been particularly voluminous in China, peaking at 4.5% market share in September 2012. By the end of last quarter, they had fallen to just 0.1%.

You can check out the smartphone sales market share over time for these markets, and others, with the interactive Kantar Worldpanel ComTech visualization tool.

Editor's note: This article was edited shortly after publishing to correct references to 'the UK', which should have referred to 'Great Britain'.