This is a job for using mobile phone and satellite imaging data (objective observations), not surveys, which are somewhat unreliable around religion. Think like a hedge fund.

Citation:

Hackett, Conrad. 2026. “Has there been a Christian revival among young adults in the U.K.? Recent surveys may be misleading.” Pew Research Center. https://doi.org/10.58094/k9vn-k647

https://www.graphsaboutreligion.com/ is also a resource on this topic.