I don't. I've been FIREd for a little over 3 years now, and the combination of good market returns plus lower spending than planned has resulted in a very low withdrawal rate. We aimed for a 3.7%-4% withdrawal rate, but since we're living how we want to live far below that I don't see any need to spend any time thinking about inflation or returns. For us it would be a little bit of work without any benefit. Each year in December I do a brief "report", but since the overall withdrawal rate is low it's not worth diving any deeper.