2 Answers

I think you need to establish where your statistics come from.

Atheists by definition have no respect for Gods law and therefor no respect for his marriage arrangement. Many feel it is alright just to live together and split when they fancy a change.

In UK many young women can live a better life as a single parent on benefits and a house provided by the state. What incentive is there to have a husband especially a drunk, druggie or sexual pervert who may become violent.

The result; you may have seen the riots in Britain, in the news caused by Ferrel kids who imagine that everybody else owes them a free living.

On the other hand I call regularly on atheistic families who do have good marriages and very respectful children. 

Then again there are so many divisions in what people think is Christianity it is hardly surprising that their are double standards and incompatibility not to mention physical abuse.

and "because of the increasing of lawlessness the love of the greater number will cool off." Matt 24:12

I hope this will give you some insight into a very complex social problems.

Regards