I have been keeping track of how long I spend reading each year for the last four years. The range is between 350 and 500 hours annually. This translates to between 30 and 40 books depending on length and difficulty.

What the tracking taught me: I read significantly more in winter. I read less when I'm anxious. I read more poetry when I'm processing something. I spend more time on non-fiction than I used to — it's crept up from about 10% to about 25% of my reading time over four years.

I don't track in order to optimize. I track because the pattern is a portrait of my inner life at a given time that I find more honest than a diary. A diary can be curated. What you read when you're unhappy is harder to lie about.