Reinsurance

Thirteen major companies account for approximately 91 percent of our reinsurance recoverable at December 31, 2017, and all are rated A or better by A.M. Best Company (AM Best) or are fully securitized by letters of credit or investment-grade fixed maturity securities held in trust. Approximately eight percent of our reinsurance recoverable relates to business reinsured either with companies rated A- or better by AM Best, with overseas entities with equivalent ratings or backed by letters of credit or trust agreements, or through reinsurance arrangements wherein we retain the assets in our general account. The remaining one percent of our reinsurance recoverable is held by companies either rated below A- by AM Best or not rated.

Reinsurance data is as follows:



	Year Ended December 31
	2017			2016			2015
	(in millions of dollars)
Direct Premium Income	$	8,677.2		$	8,385.0		$	8,151.9
Reinsurance Assumed	230.0			236.3			202.8
Reinsurance Ceded	(310.1		)	(263.6		)	(272.3		)
Net Premium Income	$	8,597.1		$	8,357.7		$	8,082.4

Ceded Benefits and Change in Reserves for Future Benefits	$	655.4		$	648.3		$	662.7

Effective October 1, 2016, we entered into a reinsurance agreement under which we ceded 30 percent of the risk for certain blocks of Unum US individual disability policies, as well as some related claims development risk for a limited period of time. The agreement is on a non-proportional modified coinsurance basis with a provision for experience refunds.