The trajectory for event cinema began to rise steeply back in 2013: For about two years, the industry worldwide saw world records being set and broken with happy regularity. Then, all of a sudden, the bubble burst. Insiders had watched this growth knowing deep down it was unsustainable, and at the time many attempted to explain the reasons behind it: the end of the recession, 100 percent digitization, a maturing market, a new trade association, or a combination of all of the above.
Source: On the Rise Again: Event Cinema Celebrates a Robust Year – Boxoffice