The Spring 2015 study shows that the overall funding shortfall for all plans increased by $5 billion for the year ending December 31, 2014, while the aggregate funding percentage decreased slightly to 80%. There has been significant recovery from the low point in 2009, but the aggregate funded percentage has yet to return to pre-2008 levels. Multiemployer plan funding levels have steadily improved, though they leveled off in 2014. For plans in need of financial recovery, the biggest driver is investment performance.