Following the news that Mayor Emanuel is prepared to support a decriminalization policy that would make the possession of 15 grams or less of marijuana a violation rather than a criminal offense, I was thinking back to Mick Dumke and Ben Joravsky's report on the racial disparities of marijuana arrests in Chicago, and wondered what it looked like across the city.

The city's data portal returned 6,453 arrests for possession of 30 grams or less of marijuana, currently a misdemeanor, from January to the end of May this year. By ward, this broke down from a high of 541 in the 28th Ward—far and away the most, 199 more than the 17th Ward—to 15 in the 43rd Ward. Here's a broad view by wards:

And here's a more finely grained map: