Who was on the DC council when you were born (if you were born after 1975, when it first came into being)? How many people have represented your ward (if you live in DC) over time?
You can learn all that and much more with a new interactive timeline from Keith Ivey. It lists everyone who's served on the council and why they left. Scroll around, mouse over the blocks for more, or click for a full screen version.
My modest contribution to this genre, by the way, is this graph of councilmembers over time whose names correspond to colors: