Hi - This is a great resource, thanks for putting it together! I am starting a
bit of research on
how long hockey players live, change in lifespan over time, and comparisons to
the national
(canada) average.

A couple of questions about the database:

Where do date of death records come from? I am curious about how much confidence
we can
put in these dates.

Some DoD fields are marked "9999" and others are blank including people born in
the 1890s
and presumably gone now. Is there a distinction here?

Cheers,

Chris Fletcher