The reconciliation above shows the Company's estimate of net losses on 2019 and prior accident years is approximately $0.3 million lower at December 31, 2020 than was provided in loss reserves at December 31, 2019 (referred to as a "reserve savings"). This compares to a reserve savings of $0.6 million on prior accident years in 2019 and a $16.8 million reserve deficiency reported in 2018 related to prior accident years. The following table is a summary of the 2020 calendar year reserve savings by accident year (dollars in thousands): Years in Which Losses Were Incurred Reserve at December 31, 2019 (Savings) Deficiency Recorded During 2020 $^{(1)}$  % (Savings) Deficiency 2019 $ 258,655 $ (1,743 ) (.7 )% 2018 158,311 4,017 2.5% 2017 65,516 (3,997 ) (6.1 )% 2016 21,374 392 1.8% 2015 16,377 858 5.2 % 2014 and prior 69,767 162 .2% $ 590,000 $ (311 ) (.1 )% (1) Consists of development on cases known at December 31, 2019, losses reported which were previously unknown at December 31, 2019 (incurred but not reported), unallocated loss expense paid related to accident years 2019 and prior and changes in the reserves for incurred but not reported losses and loss expenses. The savings shown in accident year 2019 in the table above reflects favorable loss development in short-tail lines of business, such as physical damage and occupational accident.  The deficiency shown in accident year 2018 represents deficiencies in the Company's commercial automobile business, specifically excess automobile and public transportation lines of business. The Company took and continues to take action in all accident years to reflect new trends in loss development for commercial automobile products that have emerged over the last several years. These actions include case reserving reviews, as well as continued actuarial product reviews, and resulted in the small reserve strengthening noted in accident years 2018 and prior. Bulk loss reserves are established to provide for potential future adverse development on cases known to the Company and for cases unknown at the reserve date. Changes in the reserves for incurred but not reported losses and loss expenses occur based upon information received on known and newly reported cases during the current year and the effect of that development on the application of standard actuarial methods used by the Company. The Company continues to incorporate more recent loss development data into its loss reserving formulae; however, the dynamic nature of losses associated with the commercial automobile business, as well as the timing of settlement of large claims, increases the likelihood of variability in loss developments from period to period. While the Company's basic assumptions have remained consistent, the Company continues to update loss data to reflect changing trends, which can be expected to result in fluctuations in loss developments over time. Management's goal is to produce an overall estimate of reserves which is sufficient and as close to expected ultimate losses as possible. The Company constantly monitors changes in trends related to the number of claims incurred relative to correlative variances with premium volume, average settlement amounts, number of claims outstanding at period ends and the average value per claim outstanding and adjusts actuarial assumptions as necessary to accommodate observed trends. 8