This is a wonderful project. Many thanks to Jan for sharing it.
Separately, regarding dementia, it is both less and more complicated than many commenters suggest.
From UCSF Neuroscience’s excellent Memory and Aging Center resources:
“Dementia is a general term for any disease that causes a change in memory and/or thinking skills that is severe enough to impair a person’s daily functioning… There are many different types of dementia… Most types of dementia cause a gradual worsening of symptoms over the course of years due to progressive damage to nerve cells in the brain caused by the underlying disease process…” [0]
Even more briefly: dementia is an umbrella term, many diseases can cause dementia, and those diseases may or may not be progressive.