"The number of mums who say their partner is not involved really at all in their child's care is so sad."

While that can be true, I wonder how much of it is true. It's pretty common in therapy to hear partners saying the other one doesn't contribute, but further investigation can often turn up observation biases.

That's the thing about trends in aggregate data. It tells very little about the details of any particular situation. There are almost certainly a wide variety of subgroups where this particular trend doesn't hold, and others where the changes are even more dramatic.

But the aggregate trend is quite clear.