The percentage of Catholics in the U.S. population in 2021 held steady at 21% in the latest Pew Research Center survey, issued Dec. 14.

The percentage of Protestants, however, dropped, while the percentage of "nones" -- those who profess no particular denominational attachment -- continued to rise, said the report, "About Three-in-Ten U.S. Adults Are Now Religiously Unaffiliated."

The survey results also indicate the proportion of Christians in the U.S. population continues to slide. A decade ago, they constituted 75%, or three out of every four Americans. In the new survey, that percentage is down to 63%, or five out of every eight Americans.

"Christians now outnumber religious 'nones' by a ratio of a little more than 2-to-1," the report said. In 2007, when Pew began asking its current question about religious identity, the ratio was almost 5-to-1, or 78% vs. 16%.

Since 2007, Protestantism has dwindled from 52% of all Americans to 40%, not quite twice the percentage of Catholics today. Within Protestantism, the percentage of those adults who profess evangelical or "born again" Christianity has shrunk by 6%; the number of those who are not evangelical or "born again" also has shrunk by 6%.

The dip in the percentage of Catholics is less pronounced; it was 24% in 2007 and 14 years later is 21%. The Orthodox churches make up about 1% of Americans, and members of the Church of Jesus Christ of Latter-day Saints comprises 2%.

Prayer also has taken a hit since 2007. The percentage of those who said they prayed every day then was 58%; today, it's 45%.

So too are those who consider themselves "very" religious. Fifty-eight percent of Americans had described themselves that way in 2007. Now, just 41% do. The number of those who feel "somewhat" religious has drifted downward from 28% in 2007 to 25% today. But those who say they're either "not too" or "not at all" religious has more than doubled over the past decade and a half, from 16% to 33%.

The trend lines maintained themselves on the religiosity question even after Pew switched from a random-digit-dial protocol to find survey respondents, which ended in 2019, to its National Public Opinion Reference Survey, which debuted in 2020.

Thirty-five percent of Catholics say they go to Mass at least monthly, with Hispanics outpacing whites, 36% to 33%. But those numbers are dwarfed by the 46% of Protestants who say they attend services at least monthly.

Catholics straddle the halfway mark about how often they pray -- 51% say they pray daily -- while 48% say religion is very important in their lives. Of this 48%, 54% of Hispanic Catholics say this is true for them, vs. 41% of their white counterparts.

While a combined 29% of those surveyed profess no specific religious identity, the percentage of those who say they're "nothing in particular" (20%) is more than double the combined percentage of atheists and agnostics (9%).

The Pew survey interviewed 3,937 Americans who responded either on paper or online. The margin of error for the entire respondent group is plus or minus 2.1%. Among the 860 Catholics surveyed, the margin of error is plus or minus 4.5%.