This is a trend that has been going on for decades.
Pope Francis did not curb the trend.
The obvious exception in the downward trend was Mexico which saw a 2% increase from 1995 to 2013! going from 77 to 79%. Now it is in sync with the rest at -14%!
To elaborate on the Magisterium of the Catholic Church is our mission on Plinthos (Gk. "brick"); and to do so anonymously, so that, like any brick in the wall, we might do our little part in the strength of the structure of humanity almost unnoticed.