Give a little credit to the converts, too, (6-7 million of them; 2.6% of all Americans) from Protestantism (according to Pew researchers). They are larger than either the Filipino or the Vietnamese congregations. According to the evangelical magazine CHRISTINITY TODAY,  "10% of Protestants are former Catholics and 8% Catholics are former Protestants." 

And though everyone picks on the French CC, still two-thirds (66%) of the French self-identify as Catholic, compared with the UK where barely 15% of the UK population self-identify as Anglican (the state church). If the trend continues, the English CC will outnumber the established church membership.