Online shoppers in the United States spent significantly more on their mobile devices during the 2016 holiday season and during the fourth quarter of 2016 as a whole, according to a just-released report from web measurement firm comScore Inc.

Shoppers spent $22.7 billion via their mobile devices (smartphones and tablets) during the fourth quarter, up 45.5% from $15.6 billion in Q4 2015. That growth helped push total online sales (desktop and mobile) during the fourth quarter to $109.3 billion, up 18.2% from $92.5 billion during Q4 2015.

Here’s how mobile and desktop spending looked during the fourth quarter:

The U.S. Commerce Department will report fourth quarter and full-year 2016 U.S. e-commerce sales on Friday.

Meanwhile, in a separate blog post, comScore reports shoppers spent $17.1 billion on mobile devices during the 2016 holiday shopping season, which it defines as November and December, up 44.9% from $11.8 billion in mobile sales during holiday 2015. Adding mobile sales to comScore’s previously reported $63.1 billion in desktop spending means shoppers spent a total of $80.2 billion online during the holiday shopping season, up 17.4% from $68.3 billion for desktop and mobile spending in the year-ago period.

While mobile sales growth is dramatically outpacing desktop in terms of growth, desktop still dominates overall online sales. Mobile accounted for 20.8% of overall web sales during the fourth quarter and 21.3% of overall web sales during the holiday shopping season. Last year, mobile accounted for 16.9% and 17.4% of overall sales during the respective time frames.