Did I estimate 15% based on these same pics, or others? Based on these i'd say around 14% which is great because the number is dropping, at least IMO.

What's weird is that you're 183lbs. I'm 5'11 and feel we have similar builds and bodyfat - yet i'm 195lbs. I don't think I much much more LBM then you, if any at all. I guess it could just come down to bone structure/density in these cases.

Either way, great job bro, looking good and there are a million people MY age (35) that would kill to look like you do now, remember that.