Is that a decline in the *rate* or a decline in the overall *number*?

If it's the number... a lot of people have moved out of CA lately. I would bet they skew heavily toward kid-having age families, since school closures and the possibility of school V-mandates were a big driver of this.

If we now find that rates have also declined in the states that massive numbers of people are moving *to*... that'd paint a very different picture.