Christianity is gone: the rise of a non-Christian Europe
The survey of 16- to 29-year-olds found the Czech Republic is the least religious country in Europe, with 91% of that age group saying they have no religious affiliation. Between 70% and 80% of young adults in Estonia, Sweden and the Netherlands also categorize themselves as non-religious.
The most religious country is Poland, where 17% of young adults define themselves as non-religious, followed by Lithuania with 25%. ...
https://www.theguardian.com/world/2018/mar/21/christianity-non-christian-europe-young-people-survey-religion
In the European Countries listed below, 50% or more of young people in the 16 to 29 year old group say that they have no religious affiliation. In other words, they are atheists. See the original article for a chart listing all the European countries and the percentages of religious affiliation.
Czech Rep.
Estonia
Sweden
Netherlands
UK
Hungary
Belgium
France
Finland
Denmark
Norway
Spain
In Portugal, the group of young people under 30 who have no religious affiliation is about 40%. That is high for a country that is to preserve the faith according to Sister Lucy of Fatima. Thankfully, studies also show that as young people begin to have children, they usually return to the faith, but this may no longer be the case if their parents never raise them in the faith initially.
There are other charts at the website that show the attendance at church services and the percentages of those who pray. These are quite dismal results.