Just did analysis of attack data in Iraq from Jan 2014-Oct 2015. Shows that security incidents in Iraq have been going down since start of last year. It appears that after IS seized Mosul it was focused upon consolidating its hold over territory it held. Did make one big push in winter 2014-15 in north Iraq but that failed. One of IS's main slogans is endure and that's what it looks to be doing in Iraq. Lots of charts and figures as well. Here's a link.