We measure growth by monitoring changes in gross premiums written and net premiums written. We measure underwriting profitability by examining losses and settlement expenses, underwriting expenses and combined ratios. We also measure profitability by examining underwriting income (loss) and net earnings (loss).
As discussed earlier, the estimation of our reserves is based on several actuarial methods, each of which incorporates many quantitative assumptions. The judgment of the actuary plays an important role in selecting among various loss development factors and selecting the appropriate method, or combination of methods, to use for a given accident year. The ranges presented above represent the expected variability around the actuarially determined central estimate. The total range around our actuarially determined estimate varies from (11.7)% to 4.6%. As shown in the table below, since 2015 the variance in our originally estimated accident year loss reserves has ranged from (1.3)% deficient to 8.0% redundant as of December 31, 2020.
ICC Holdings, Inc. secured a loan with a commercial bank in March 2017 in the amount of $3.5 million and used the proceeds to repay ICC for the money borrowed by the ESOP. The term of the loan is five years bearing interest at 3.65% and the Company pledged stock and $1.0 million of marketable assets as collateral for the loan.
In April 2020, the Company obtained a $1.6 million loan (the PPP loan) from a commercial bank pursuant to the federally authorized Paycheck Protection Program (Program) administered by the Small Business Administration (the SBA). The Company applied for loan forgiveness in the fourth quarter of 2020 and received full forgiveness from the SBA. Both the $1.6 million in principal and $11,000 in accrued interest were forgiven effective December 30, 2020 and recognized as a non-taxable gain on extinguishment of debt.
The following table summarizes, as of December 31, 2020, our future payments under contractual obligations and estimated claims and claims related payments for continuing operations. As of December 31, 2020, the Company had received 1,289 claims for business interruption related to COVID-19. Based on policy language, the Company does not anticipate that coverage will be triggered for these property claims requiring loss payment.
Premiums are recognized ratably over the term of the contracts, net of ceded reinsurance. Unearned premiums represent the portion of premiums written relative to the unexpired terms of coverage. Unearned premiums are calculated on a daily pro rata basis. A premium deficiency reserve should be recognized if the sum of expected claim costs and claim adjustment expenses, expected dividends to policyholders, unamortized acquisition costs, and maintenance costs exceeds related unearned premiums. The Company utilizes anticipated investment income as a factor in its premium deficiency calculation. The Company concluded that no premium deficiency adjustments were necessary in either of the years ended December 31, 2020 and 2019.
As of December 31, 2020, the Company held 111 equity securities that were in unrealized loss positions. Of these 111 securities, 35 were in an unrealized loss position for 12 consecutive months or longer prior to December 31, 2019.
U.S. Treasury Bonds, Common Stocks, and Exchange Traded Funds-U.S. treasury bonds and exchange traded equities have readily observable price levels and are classified as Level 1 (fair value based on quoted market prices). All common stock holdings are deemed Level 1.