Not seen the 10% link but did you read the post that was linked by @nickcs (reply 7) Nate published his TR data for the bell curve of cyclists, this is for active TRusers… it shows an .25FTP/kg approx every 10 years on the bell curve. Thread is a good read if you have the time. You might have already read this and apologies if you have.
Top of bell curve for men
18-30 : 3.25 - 3.5 FTP/kg
30-40 : 3.0 - 3.25 FTP/kg
40-50 : 2.75 - 3.0 FTP/kg
50-60 : 2.75 - 3.0 FTP/kg
60-80 : 2.25 - 2.5 FTP/kg