Quick hack: list attendees year of birth in course summary
[confetti] / pages /
drwxr-xr-x   ..
-rwxr-xr-x 7821 attendees.sh
-rwxr-xr-x 4964 courses.sh
-rwxr-xr-x 785 email.sh
-rwxr-xr-x 141 error.sh