Evanston lost 569 registered voters from 2005 to 2009.
That's not a lot but the story is in the details. Here below is a list of gains/losses by ward sorted by size.
Ward Change '05-'09
1 -203
5 -193
9 -175
3 -134
7 -91
4 -79
2 57
8 86
6 163
1st Ward: The second precinct gained 389 registered voters, probably due to the sale and occupancy of new condominium units in the Optima Towers, Optima Horizons, and Sherman Plaza developments. However, The 4th, 5th and 6th precincts lost a total of 528 registered voters, perhaps due to students changing their registration to a home state. These wards are bounded roughly by Foster(N), Dempster(S), Sheridan(E) and a zig-zag W line starting with Judson on the South and ending with Sherman on the North. They include a large portion of the East and South sections of the downtown area. If these assumptions are correct, voter demographics in this election made a significant shift from students to residents, and if so, likely also upward in age bracket and income. However, that shift is likely an anomaly. Normally, a presidential campaign produces a surge in student registrations in Evanston. In 2008 the Obama campaign urged students to register in a state other than Illinois.
5th Ward lost 215 registrations in the 1st and 2nd precinct: Noyes(N) Emerson(S) Sherman(E) Ridge(W). Again, this area has a large student population.
9th Ward lost registrations in the 1st, 3rd, and 7th precincts: Main(N), Austin(S), Chicago(E), Ridge(W)
3rd Ward had gains but the 5th precinct lost 105: Main(N), Keeney(S) Judson(E) and Chicago(W). This precinct included The Main which has been torn down.
7th Ward had a loss of 107 in the 9th precinct comprising the North end of the NU campus from Sheridan to the Lake North of Library Place.
4th Ward was mixed, with five precincts losing registration and three gaining.
2nd Ward was mixed but there was a gain of 109 in the 1st Precinct, a panhandle bordered by roughly Emerson(N), Lake(S), Benson(E) and Dodge(W), which includes the 25-story Optima Views high-rise.
8th Ward was mixed but with a total gain of 147 in the 3rd, 5th and 6th precincts, all bordering Howard street from Chicago to Dodge, where there have been a number of smaller infill developments.
6th Ward had two precincts lose and eight gain. The 8th Precinct had a gain of 115 due to the opening of the expanded Three Crowns retirement community: Colfax(N), Elgin/Emerson/Golf(S), Pioneer(E) and Ewing(W).