so after wrestling with excel for entirely too long, I have a chart sans events with a linear regression showing an increase in violence over time and a chart with percent change over time. But I don't know how to apply these to show correlation?? i dropped most of pre-independence too for clarity. percent change chart not included because it's entirely too many data points to make sense right now. Clean chart below, still need to put events in 
Wish I had a moment to help but busy until tomorrow. What I meant was to calculate the percent change in terror deaths after a security measure was put in place, and compare to times before the measure was adopted. Your final graph might only have two bars. Send me your raw data with the timeline, and I'll make an example of what I'm trying to say tomorrow morning, if you don't mind me butting in. Otherwise I'll just try to explain better when I have more time.
No worries! It's not due til Thursday. I'll shoot you that info when I'm back at my desk. Thanks for all your help!