July 2017: 77 killed, 355 wounded 17.8% Lethality rate
July 2016: 74 killed, 382 wounded 16.2% Lethality rate
July 2015: 58 killed, 271 wounded 17.6% Lethality rate
July 2014: 47 killed, 277 wounded 14.5% Lethality rate
Data from:
http://heyjackass.com/category/2017-commentary/Lethality rate I calculated. Trend of lethality is essentially flat the for July 2015-2017. However, it's quite a bump up from 2014 since Rahm Emmanuel has been mayor since 2015 and is nearly 20% higher death count under his (lack of) administration.