Interesting list, but there is a problem with it. It is very difficult to surmise the degree to which Christian church attendance has declined from that data because it is so likely to be conflated with a growing population of Muslims that is very reliable in their “church” attendance.
France is about 10% Muslim. Which can only mean that the data certainly understates significantly the lack of Catholic religious observance in France for 2 reason.
Muslims are remarkably observant of their faith. Thus the 60% non-attendee number will include few Muslims, while the remaining 40% (attendee) number will include almost all of the 10% Muslim population.
Making matters worse, the remaining 40% (attendee) number includes both regular attendees and occasional attendees. I have little doubt that (among this 40%) the percent of the French-Catholics who attend church ONLY occasionally far exceeds the percent of the French-Muslims who attend mosque ONLY occasionally. Why? French-Catholics live in secular communities, while French-Muslims live in religiously defined and observant communities.
Which makes the point of my post even more stronger: If France does fall to Islam it will NOT be because "France is too Catholic to save herself."