How habit-improvement years are estimated

The page looks for answers that did not receive full points, then estimates how much upside those weaker answers might represent.

Smoking, exercise, drunk driving, and core lifestyle behaviors generally carry more upside than smaller items because they also carried more downside in the score.

The point of this module is prioritization. It is trying to say where the biggest recoverable upside might be, not provide a literal physician-grade year estimate.