The latest Insurance Institute for Highway Safety statistics about bikes are available: http://www.iihs.org/research/fatality.aspx?topicName=Bicycles&year=2011.
(edit 3/2014: now all these fatality fact sheets are under http://www.iihs.org/iihs/topics/t/pedestrians-and-bicyclists/fatalityfacts/bicycles)
Riskiest riding seems to involve men over 20 years of age, riding at dusk, urban areas, being drunk, or riding without a helmet. So the impression you get of who is a dangerous rider when you're out on Milwaukee Ave seems to be accurate. Notice that although the demographics of riders have changed a lot over time, the absolute overall fatalities have remained relatively constant. Are there more riders total now than in the 1970s and 1980s? Was there a group of especially unsafe boys growing up in the mid-1970s who are still getting into accidents? Interesting statistics.