Games generated approximately 85 percent of mobile app market revenue in 2015, representing a total of $34.8 billion across the globe, according to a report on the app economy by market researcher App Annie.

The data is part of a larger report by App Annie on the growth of all mobile apps. The overall app economy is expected to grow from $51 billion to $101 billion by 2020. That report also says that games will hit $41.5 billion in 2016 and reach $74.6 billion by 2020. And if you add up all of the game-related revenues in all sectors, you’ll find that gaming has become monstrously big around the world.

The growth in gaming will come from strong monetization in mature markets, especially China’s tier-one and tier-two cities, as well growth in as Japan and South Korea. See our other story for more details.

It’s worth noting that other sources of forecasts have different outlooks for gaming, and they slice the data in different ways. Tech advisor Digi-Capital expects the game-software industry to grow 22 percent from $90 billion a year in 2016 to $115 billion a year by 2020. Digi-Capital said that the game industry continues a big transition as market leaders are consolidating their positions as different sectors ebb or grow. The growth rate is healthy, but it isn’t as big as in past years as the overall industry becomes more mature.

Meanwhile, market researcher EEDAR estimates that the total console software and hardware market revenues were $44 billion in 2015. And Jon Peddie Research estimates that worldwide PC gaming hardware sales will grow from $24.6 billion in 2015 to $26.1 billion in 2016. PC gaming hardware is expected to grow to $30 billion by 2018.

Meanwhile, the Open Gaming Alliance says that it expects PC gaming software to increase from $26 billion in 2014 to $35 billion by 2018.