Zero.

I totally appreciate the value in it, but I'm old and just have a hard time making personal growth in my job skills a priority over time with family. I read more before I had children, and I would read if I was could spend some work hours on it.

I've also seen people who read too much - all their work philosophy and decisions are not based on experience, but on a book they read. I feel the flow should be to: read -> synthesize new info with experience -> test out some changes to your way of working -> decide whether or not it works. But I've seen too much of: read -> declare sweeping changes to the entire team -> read another book.