Here is a chart showing the vote for all the cities in Minnesota over 1,000 population from 1976 to 1996. I did all this a long time ago, so I was only interested in the vote by AREA back then, and actually did it all by hand, so only the larger cities are listed from 1956 to 1972. But I hope some people will find this very useful! Working on 2000 to 2012, which I can get the raw data off the SOS website. Usually a town or village will have about the same amount of votes from election to election and then all the sudden have increases take place. This is how I calculate them to become suburban.
http://www.scribd.com/doc/220576985/1956-to-1996-MINNESOTA-for-PRESIDENT