Christianity Declining

From 2010 to 2020, these countries saw over 10% of their population stop describing themselves as Christian: Australia (-20%), Chile (-18%), Uruguay (-17%), the USA (-14%), Canada (-14%), the UK (-13%), Austria (-12%), Sweden (-12%), Switzerland (-12%), Ireland (-11%), France (-11%) and Belgium (-10%), with Finland and Spain close behind.

The largest increase in Christianity in a country in that period was in Mozambique (+5.0%).

See humanreligions.info/christianity.html section #2 on Worldwide Numbers.