With 2013 drawing to a close, the good folks at AdDuplex are providing their final peek at Windows Phone usage statistics for the year. Not surprisingly, we see year-long trends expressed in the monthly results: Low-end devices continue to carry the day and the expensive high-end handsets are nowhere to be see in the top 10.

This is one of the reasons I declared recently that the Nokia Lumia 520 is the Best Tech Deal of 2013. Despite my personal affection for the high-end Lumia 1020, which is my personal daily-carry smart phone, the only reason we're still talking about this platform is that the lower-end devices—the Lumia 520, 521, 525 and 620—are keeping Windows Phone afloat.

Last month, AdDuplex reported that the Lumia 520 alone represented 35.3 percent of all Windows Phone 8 handset usage worldwide. That's one out of every three Windows Phone 8 handsets. And with the supposedly-lowly 520 being bargain discounted throughout the holidays, it probably won't surprise you to discover that usage is up even more: Among Windows Phone 8 handsets, the Lumia 520 now owns 39.3 percent usage share. And the Lumia 520, 521, and 620 together are a combined 53.8 percent of the market. Almost 60 percent.

In the United States, which is not a strong market for Windows Phone yet, though I'm wondering whether these low-end devices will change that, the Lumia 521 and 520 together represent 42.4 percent of all Windows Phone handsets (all versions) used. Three times as many people use the Lumia 521 as use the high-end Lumia 920. And the flagship Lumia 1020, with just 2.3 percent usage share, barely makes the top 10 in this country, coming in at number 8 and behind the Huawei Ascend W1 somehow. It doesn't rate worldwide at all.

Lumia 521 usage in the US is so high, in fact, that T-Mobile is now the number two carrier for Windows Phone in the United States with 23.3 percent usage share. That's behind AT&T (31.7 percent) but ahead of Verizon (20.9 percent.) Verizon needs that Lumia 929, stat.

A few other stats from the AdDuplex report:

Almost no high-end phones are popular. Worldwide, only the Lumia 920 makes the top 10 list for usage among all Windows Phone handsets, and if you look just at Windows Phone 8 handsets, only two high-end devices make the list: The Lumia 920 and the 925. In the US, there are three: The Lumia 920, 928, and 1020. All the rest are new low-end devices or old devices. The Lumia 1520 phablet doesn't appear anywhere in this report.

Nokia dominance continues to grow. This month, Nokia grew from 90 percent usage share to 92.1 percent. HTC is a distant number two with 5.2 percent usage. Samsung is at 1.6 percent and Huawei is at 1.1 percent.

Windows Phone 8. Microsoft's latest mobile OS version now accounts for 78.3 percent of all Windows Phone handsets in use, up from 75.3 percent last month.

As you may remember, AdDuplex bills itself as the largest cross-promotion network for Windows Phone and Windows 8 apps, empowering developers and publishers to promote their apps for free by helping each other. And each month it provides a tantalizing glimpse at which Windows Phone (and Windows) devices people are actually using.

The AdDuplex Windows Phone Statistics Report for December 2013 will be available publicly tomorrow.