If you think you’re seeing more video ads, you’re right: In the past year, there has been a huge increase in the number of video ads displayed on web pages.

According to comScore, in December 2011, only 14 percent of videos had ads attached to them, but in December 2012, that portion was 23 percent.

It estimates that 84.9 percent of the U.S. Internet audience viewed online video in December 2012.

Here’s a chart showing how both the number of online videos and their corresponding ads have increased in the last 12 months. This metric shows what percentage of video views are being monetized with video ads.

So where are people watching videos? Not surprisingly, YouTube, a Google site, takes the top prize.

Google site users also had the highest average engagement among the top ten platforms, as indicated by the amount of time viewers spent on the sites. ComScore says “the duration of the average online content video was 5.4 minutes, while the average online video ad was 0.4 minutes.”

Facebook, not typically considered video site, comes in at number two, while music video service VEVO takes third place.

According to the data, 182 million U.S. Internet users watched 38.7 billion online content videos in December:

When it comes to sites with the most video ads viewed, Google’s sites also win. Facebook and VEVO didn’t break the top 10 this time, but video streaming site Hulu did. According to comScore:

• Time spent watching video ads totaled 4.1 billion minutes
• The BrightRoll Video Network delivered the highest duration of video ads at 966 million minutes.
• Video ads reached 53 percent of the total U.S. population an average of 70 times during the month.
• Hulu delivered the highest frequency of video ads to its viewers with an average of 65.
• Google delivered an average of 20 ads per viewer.

All in all, comScore’s data shows “video ads accounted for 22.6 percent of all videos viewed and 1.9 percent of all minutes spent viewing video online.”