I don't believe it's that linear.
The anecdotal evidence is that once you start getting into the low 90's you will see a noticable drop-off in performance and increased risk of injury.
© 1999- WhatIfSports.com, Inc. All rights reserved. WhatIfSports is a trademark of WhatIfSports.com, Inc. SimLeague, SimMatchup and iSimNow are trademarks or registered trademarks of Electronic Arts, Inc. Used under license. The names of actual companies and products mentioned herein may be the trademarks of their respective owners.