Publishers could lose almost $22 billion in revenue for the year due to ad-blocking software, with the number of users installing such software increasing worldwide by 41 percent year-over-year.

While the number of monthly active users with ad-blocking software now stands at 198 million, representing only 6 percent of the population, the $22 billion that publishers stand to lose is equivalent to about 14 percent of global spending on advertising.

The figures are according to the 2015 Ad Blocking Report that PageFair published in partnership with Adobe.

According to PageFair and Adobe, the global cost of ad-blocking software could reach as high as $41.4 billion next year. In addition, while the 41 percent increase this year is lower than the almost 70 percent growth posted from 2013 to 2014, the issue has become a cause for concern among publishers.

"Ad blocking is a viral phenomenon that will continue," said PageFair head of ecosystem Johnny Ryan in an interview with Business Insider, adding that  the majority of users with ad-blockers learn about the software through word of mouth and through their own research online.

The rate of ad-blocker usage is different across countries, with the United States having about 45 million monthly active users of ad-blocking software, an increase of 48 percent compared to last year. Across Europe, the percentage is at 35 percent.

PageFair and Adobe have previously found out that users of ad-blocking software are usually young and technically savvy males.

Currently, most ad-blocking occurs on desktop computers, despite 38 percent of Internet browsing being done on mobile devices. Only 1.6 percent of ad-block traffic originate from mobile devices.

Publishers should even be more worried though, as ad-blocking technology could become a more mainstream technology. Developer documents for the iOS 9 of Apple reveals that it will allow app developers to create ad-blocking software for the first time for iOS devices.

This would be a "game changer" according to PageFair and Adobe, as the Safari browser of Apple constitutes 52 percent of mobile Internet browsing and 14 percent of total Internet browsing. If ad-blocking software would become easier to install once iOS 9 is released, ad-blocking figures could soar even higher.

Only time will tell if such a thing happens though, with the iOS 9 scheduled to be released in the fall.