The following development tables provide the incurred and paid losses and allocated loss adjustment expenses, net of reinsurance, for workers’ compensation and general liability for accident years 2010 through 2019. The incurred but not reported (“IBNR”) losses and claims frequency is included for each accident year presented.

	Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance																				As of
	For the Years Ended December 31,																				December 31, 2019
	(Dollars in thousands)																				Total IBNR
																					Plus
																					Expected		Cumulative
																					Development		Number of
Accident	Unaudited (1)																				on Reported		Claims
Year	2010		2011		2012		2013		2014		2015		2016		2017		2018		2019		Claims		Reported
2010	$	179,156	$	202,479	$	208,035	$	205,769	$	198,861	$	193,029	$	191,000	$	189,403	$	189,040	$	188,096	$	5,093		5,971
2011		—		196,384		199,522		199,163		198,213		195,262		192,988		191,126		189,327		188,226		6,008		6,044
2012		—		—		222,549		222,075		212,738		193,515		184,460		182,859		180,387		178,586		6,834		5,749
2013		—		—		—		241,810		241,811		233,656		220,457		214,701		210,588		209,184		8,803		5,766
2014		—		—		—		—		268,846		268,846		249,097		235,058		226,933		218,386		6,534		5,838
2015		—		—		—		—		—		262,573		262,573		252,514		235,471		220,965		12,488		5,515
2016		—		—		—		—		—		—		250,491		250,491		241,406		218,005		11,377		5,390
2017		—		—		—		—		—		—		—		244,094		244,098		234,587		14,636		5,199
2018		—		—		—		—		—		—		—		—		250,487		250,487		13,900		5,451
2019		—		—		—		—		—		—		—		—		—		241,344		18,973		4,959
																	Total		$	2,147,866	$	104,646

	Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance
	For the Years Ended December 31,
	(Dollars in thousands)

Accident	Unaudited (1)																				Claim
Year	2010		2011		2012		2013		2014		2015		2016		2017		2018		2019		Frequency (2)
2010	$	47,520	$	108,714	$	141,029	$	156,974	$	165,834	$	169,565	$	172,426	$	175,019	$	176,663	$	177,331		24.94
2011		—		53,329		111,029		140,831		153,968		161,639		165,967		167,757		169,994		170,785		22.82
2012		—		—		50,579		107,467		133,658		149,161		154,553		157,207		159,807		161,014		18.73
2013		—		—		—		51,396		119,507		150,304		165,994		172,479		177,724		180,614		16.55
2014		—		—		—		—		53,060		119,820		153,320		169,736		180,683		186,129		14.99
2015		—		—		—		—		—		54,141		121,599		151,818		170,461		182,053		14.25
2016		—		—		—		—		—		—		52,238		115,713		143,016		156,861		14.22
2017		—		—		—		—		—		—		—		56,951		122,552		151,427		14.64
2018		—		—		—		—		—		—		—		—		62,061		126,057		15.16
2019		—		—		—		—		—		—		—		—		—		58,883		14.50
																	Total			1,551,154
All outstanding liabilities before 2010, net of reinsurance																				80,832
Liabilities for loss and loss adjustment expenses, net of reinsurance																				677,544

(1) Data presented for these calendar years is required supplementary information, which is unaudited.
(2) Frequency, as calculated above, refers to reported claims divided by gross premium earned.

The average annual percentage payout of incurred losses by age, net of reinsurance, for workers’ compensation and general liability as of December 31, 2019 is summarized below. Since workers’ compensation has long payout periods, the table below shows less than 100% in the years disclosed. This is required supplementary information, which is unaudited.

The following table provides a reconciliation of the beginning and ending reserve balances, net of related amounts recoverable from reinsurers, for 2019, 2018 and 2017:

	Year Ended December 31,
	2019			2018			2017
	(in thousands)
Balance, beginning of period	$	798,409		$	771,845		$	742,776
Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses		107,216			84,889			78,256
Net balance, beginning of period		691,193			686,956			664,520
Add incurred related to:
Current accident year		241,344			250,487			244,094
Prior accident years		(65,002	)		(45,596	)		(34,770	)
Total incurred		176,342			204,891			209,324
Less paid related to:
Current accident year		58,883			62,061			56,951
Prior accident years		131,108			138,593			129,937
Total paid		189,991			200,654			186,888
Net balance, end of period		677,544			691,193			686,956
Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses		95,343			107,216			84,889
Balance, end of period	$	772,887		$	798,409		$	771,845

The foregoing reconciliation reflects favorable development of the net reserves at December 31, 2019, 2018 and 2017. The favorable development reduced loss and loss adjustment expenses incurred by $65.0 million in 2019, driven primarily by accident years 2016 and 2015 of $23.4 million and $14.5 million, respectively. In 2018 and 2017, the Company recorded favorable development of $45.6 million and $34.8 million, respectively. The revisions to the Company’s reserves reflect new information gained by claims adjusters in the normal course of adjusting claims and is reflected in the financial statements when the information becomes available. It is typical for more serious claims to take several years or longer to settle and the Company continually revises estimates as more information about claimants’ medical conditions and potential disability becomes known and the claims get closer to being settled. Multiple factors can cause loss development both unfavorable and favorable. The favorable loss development we experienced across accident years was largely due to favorable case reserve development and continued favorable severity trends compared to those originally estimated.

Reserves established for workers’ compensation insurance includes the exposure to occupational disease or accidents related to asbestos or environmental claims. The exposure to asbestos claims emanate from the direct sale of workers’ compensation insurance. These claims resulted from industry workers who were exposed to tremolite asbestos dust and electricians and carpenters who were exposed to products that contained asbestos. There has been no known exposure to asbestos claims arising from assumed business. The emergence of these claims is slow and highly unpredictable. The Company estimates full impact of the asbestos exposure by establishing full case basis reserves on all known losses. Reserves for losses incurred but not reported (IBNR) include a provision for development of reserves on reported losses. Reserves are established for loss adjustment expenses (LAE) associated with these case and IBNR loss reserves.

The Company has historically written general liability coverages that are reported in other liability lines of business. These coverages may be associated with the property and casualty industry’s exposure to environmental claims. However, the Company has not been notified by any insured for which exposure exists due to these types of claims. Company management believes potential exposure to environmental claims to be remote. Therefore, the Company has no loss or loss adjustment expense reserves for such liabilities.

The anticipated effect of inflation is implicitly considered when estimating liabilities for loss and loss adjustment expenses. In establishing our reserves for loss and loss adjustment expenses, we review the results of analyses using individual case-base valuations and statistical and actuarial methods that utilize historical loss data from our more than 34 years of underwriting workers’ compensation insurance. The actuarial analysis of our historical data provides the factors we use in estimating our loss reserves. These factors are primarily measures over time of the number of claims paid and reported, average paid and incurred claim amounts, claim closure rates and claim payment patterns. In evaluating the results of our analyses, management also uses substantial judgment in considering other factors that are not considered in these actuarial analyses, including changes in business mix, claims management, regulatory issues, medical trends, employment and wage patterns, insurance policy coverage interpretations, judicial determinations and other subjective factors. Due to the inherent uncertainty associated with these estimates, and the cost of incurred but unreported claims, our actual liabilities may vary significantly from our original estimates. These anticipated trends are monitored based on actual development and are modified if necessary.