A Catholic priest offering the Mass. (YouTube)

(CNSNews.com) -- An updated survey from Gallup, which it has conducted every 10 years since 1955, shows that only 39% of Catholics and 45% of Protestants attend church weekly. Back in 1955, about 75% of Catholics went to Mass every week. For the Protestants, about 42% went to church weekly.

So, church attendance has remained pretty steady for Protestants -- although they are fewer in number now than in 1955 -- but church attendance for Catholics has declined dramatically and, as Gallup reports, continues to fall.

The steepest drop in Mass attendance for Catholics (more than 20%), said Gallup, occurred between the 1950s and 1970s. It then started to fall about 4% each decade and in this last decade dropped 6%.

(YouTube)

Gallup said the changes became very clear in the 1960s -- that was a period of major social upheavel, which included the sexual revolution, and the liberal "reforms" introduced into the Catholic Church through Vatican II.

"In 1955, practicing Catholics of all age groups largely complied with their faith's weekly mass obligation," said Gallup. "At that time, roughly three in four Catholics, regardless of their age, said they had attended church in the past week. This began to change in the 1960s, however, as young Catholics became increasingly less likely to attend. The decline accelerated through the 1970s and has since continued at a slower pace."

"Meanwhile, since 1955, there has also been a slow but steady decline in regular church attendance among older Catholics," said the survey. "This includes declines of 10 points or more in just the past decade among Catholics aged 50 and older, leading to the current situation where no more than 49% of Catholics in any age category report attending church in the past week." (Emphasis added.)

The findings were more positive for Protestants. "U.S. Protestants' church attendance was not nearly as high as Catholics' in the 1950s -- but it has not decreased over time," said the polling firm. "Currently, the rate of weekly church attendance among Protestants and Catholics is similar at most age levels. One exception is among those aged 21 to 29, with Protestants (36%) more likely than Catholics (25%) to say they have attended in the past seven days."

However, the number of Americans identifying as Protestants is shrinking, noted Gallup, from 71% in 1955 to 47% in the mid-2010s. For comparison, only 22% of Americans identify as Catholics today. That number was 24% in 1955. The percentage of Catholics is holding fairly steady today because of the growth of the U.S. Hispanic population.

Protestant church. (Youtube)

For young people, the numbers are not positive. Gallup found that for Protestants, ages 21-29, only 25% attend church once a week. For Catholics, that number was 12%.

"After stabilizing in the mid-2000s, weekly church attendance among U.S. Catholics has resumed its downward trajectory over the past decade," said Gallup. "In particular, older Catholics have become less likely to report attending church in the past seven days -- so that now, for the first time, a majority of Catholics in no generational group attend weekly."

"Further, given that young Catholics are even less devout, it appears the decline in church attendance will only continue," said the survey firm. "One advantage the Catholic Church has is that the overall proportion of Americans identifying as Catholic is holding fairly steady. However, that too may not last given the dwindling Catholic percentage among younger generations."

"All of this comes amid a broader trend of more Americans opting out of formal religion or being raised without it altogether," reported Gallup. "In 2016, Gallup found one in five Americans professing no religious identity, up from as little as 2% just over 60 years ago."