The following table presents changes in mortgage servicing rights for the periods presented:


(dollars in thousands)
Balance at December 31, 2022	$	9,074
Additions	58
Amortization	(189)
Balance at March 31, 2023	$	8,943

Balance at December 31, 2021	$	9,738
Additions	276
Amortization	(534)
Balance at March 31, 2022	$	9,480

Income generated as the result of new mortgage servicing rights is reported as gains on sales of loans and totaled $0.1 million for the three months ended March 31, 2023, compared to $0.3 million for the three months ended March 31, 2022.

Amortization of mortgage servicing rights totaled $0.2 million for the three months ended March 31, 2023, compared to $0.5 million for the three months ended March 31, 2022.

The following tables present the fair market value and key assumptions used in determining the fair market value of our mortgage servicing rights:


	Three Months Ended March 31,
(dollars in thousands)	2023			2022
Fair market value, beginning of period	$	12,061		$	10,504
Fair market value, end of period	11,875			11,166
Weighted average discount rate	9.5		%	9.5		%
Weighted average prepayment speed assumption	10.3		%	18.3		%

The carrying values and accumulated amortization related to our mortgage servicing rights are presented below:


	March 31, 2023						December 31, 2022
(dollars in thousands)	Gross Carrying Value		Accumulated Amortization		Net Carrying Value		Gross Carrying Value		Accumulated Amortization		Net Carrying Value

Mortgage servicing rights	$	69,471	$	(60,528)	$	8,943	$	69,413	$	(60,339)	$	9,074

Based on the mortgage servicing rights held as of March 31, 2023, estimated amortization expense for the remainder of fiscal year 2023, the next five succeeding fiscal years and all years thereafter are as follows:


(dollars in thousands)
Year Ending December 31,
2023 (remainder)	$	668
2024	833
2025	756
2026	684
2027	610
2028	548
Thereafter	4,844
Total	$	8,943