We always keep Top Grossing 200 games up to date. In addition to that, some of the key factors we track in our database are diversity and representativeness.
Diversity means that we don't only focus on the most successful game genres or games: in order to be able to make statistically sound findings on the most important features driving commercial success we need to have a lot of variety in our database.
Representativeness means that we have a sample size of different game types that is high enough for statistically sound conclusions based on it. For example, in order to find drivers of success in match 3 puzzle games we need to have enough match 3 games in our database.