If someone showed you a chart with the day’s top five highest grossing mobile games, it’d be near impossible to tell whether you were looking at a chart from today, two years ago, or, in all likelihood, two months from now.

Since late-2013, Candy Crush, Clash of Clans and Game of War have been three of the top five highest grossing games for iOS devices, according to data from app analytics firm App Annie. Candy Crush, the oldest of the three games, hasn’t been below the top five in over one thousand days. It helps that all three games are free to install, deriving most of their revenue from in-app purchases such as players paying for access to higher game levels.