From looking at the data, it looks like "years that teams have been in league" or "years that teams have been in their current city (for Colorado, New Jersey) would have a strong correlation. The Original 6 and teams from the initial expansions in the years after seem to do much higher ratings and have higher search interest. Given the relatively longer tenure of the Blackhawks vs the Golden Knights, you might have to do something like the Square Root of the years, but I bet that would be an even higher correlation than anything else. You also might have to throw out 2020 and 2021 b/c those were years when the Cup was moved from it's traditional early June time frame.
From looking at the data, it looks like "years that teams have been in league" or "years that teams have been in their current city (for Colorado, New Jersey) would have a strong correlation. The Original 6 and teams from the initial expansions in the years after seem to do much higher ratings and have higher search interest. Given the relatively longer tenure of the Blackhawks vs the Golden Knights, you might have to do something like the Square Root of the years, but I bet that would be an even higher correlation than anything else. You also might have to throw out 2020 and 2021 b/c those were years when the Cup was moved from it's traditional early June time frame.