Most things cannot be fairly reduced to a number, but numbers are pretty good at telling a general story.
The USCCB communications office has releasted a new set of numbers:
WASHINGTON—How many Catholics are there in the United States? What was the total enrollment of Catholic elementary and high schools in the United States last year? How many people are served by Catholic hospitals annually? The answers to these questions (77.7 million, 2 million and 88.5 million, respectively) and many other facts and statistics about the life of the Catholic Church in the United States are compiled in a new guide, “The Catholic Church by the Numbers,” issued by the Office of Media Relations of the U.S. Conference of Catholic Bishops (USCCB).
The whole set is here: www.usccb.org/about/media-relations/statistics/.
Will look more at it later.