Total interest expense for the full year of 2021 decreased by $2.9 million, or 27.9%, when compared to 2020, due to lower levels of deposit and Federal Home Loan Bank (FHLB) borrowings interest expense. Specifically, deposit interest expense in 2021 was lower by $2.8 million, or 37.0%, despite the previously mentioned increase in deposits that occurred between years. The deposit growth reflects new deposit inflows as well as the loyalty of the bank’s core deposit base. The previously mentioned late third quarter 2021 maturity of a $33 million institutional deposit that had an annual cost of 2.95%, which resulted in approximately $240,000 of interest expense savings during the fourth quarter. Additionally, management continues to effectively execute several deposit product pricing reductions to address the net interest margin challenges presented by the low interest rate environment. As a result, the Company experienced deposit cost relief. Specifically, our total deposit cost averaged 0.42% for the full year of 2021 compared to 0.74% in 2020, representing a meaningful decrease of 32 basis points. Note that total deposit cost in the fourth quarter of 2021 averaged 0.31%. Total FHLB borrowings interest expense for full year of 2021 was lower by $252,000, or 22.3%, compared to 2020. The current strong liquidity position has allowed the Company to paydown short-term and FHLB advances, which typically cost more than similar term deposit products. At December 31, 2021, total short-term and FHLB advances were $42.7 million, which is $47 million, or 52.4%, lower than the December 31, 2020 level.
As mentioned previously and described in detail in our third quarter of 2021 press release, the Company completed a private placement of $27 million in fixed-to-floating rate subordinated notes on August 26, 2021. The notes currently have a fixed annual interest rate of 3.75% and replaced subordinated debt and trust preferred securities totaling $20 million that had a weighted average cost of 7.73%. The fourth quarter of 2021 represents the first full quarter that the Company has benefitted from this strategic action to lower long-term debt costs. Specifically, this strategy favorably reduced fourth quarter 2021 interest expense by $147,000 and we expect annual interest expense on long term debt to decline by $588,000. This savings is being recognized even though the size of the new subordinated debt is $7 million higher than the debt instruments it replaced. These additional funds are being utilized for general corporate purposes, which included the downstream of $3.5 million of capital to the bank, to support future loan growth. Additionally, long term debt interest expense is higher for the full year of 2021 when compared to 2020 because the Company was required to immediately write off the remaining portion of the unamortized issuance costs from the original debt instruments in the third quarter of 2021 which amounted to $202,000. Therefore, in aggregate, when considering the reduced FHLB borrowings interest cost, total borrowing interest expense decreased by $225,000, or 31.8%, for the quarter and by $101,000, or 3.5%, for the full year.
The Company recorded a $250,000 provision expense for loan losses in the fourth quarter of 2021 as compared to a $1,075,000 provision expense recorded in the fourth quarter of 2020. For the full year of 2021, the Company recorded a $1.1 million provision expense for loan losses compared to a $2.4 million provision expense recorded in 2020. The lower 2021 provision for both time periods reflects an improved credit quality outlook for the overall portfolio due to several loan upgrades as well as reduced criticized asset levels and delinquent loan balances demonstrating improvement this year. This reflects the Company’s loan officers working effectively with our customers as the economy improves and as businesses return to normal operations with limited restrictions. As demonstrated historically, the Company continues its strategic conviction that a strong allowance for loan losses is needed, which has proven to be essential as we support certain borrowers as they fully recover from the COVID-19 pandemic. Overall, we believe that non-performing assets remain well controlled, and such assets have increased modestly in the fourth quarter totaling $3.3 million, or 0.34% of total loans, on December 31, 2021. The Company experienced low net loan charge-offs of $47,000, which equates to 0.00% of total loans, in 2021 and compares favorably to net loan charge-offs of $309,000, or 0.03% of total loans, in 2020. Since the end of the fourth quarter of 2020, the balance of the allowance for loan losses increased by $1.1 million, or 9.3%, to $12.4 million at December 31, 2021. Management continues to carefully monitor asset quality with a particular focus on loan customers that have requested an additional payment deferral. The Asset Quality Task Force is meeting at least monthly to review these particular relationships, receiving input from the business lenders regarding their ongoing discussions with the borrowers. In summary, the allowance for loan losses provided 373% coverage of non-performing assets, and 1.26% of total loans, on December 31, 2021, compared to 341% coverage of non-performing assets, and 1.16% of total loans, on December 31, 2020. Note that the reserve coverage of total loans, excluding PPP loans, is 1.28%(1) on December 31, 2021. The Small Business Administration guarantees 100% of the PPP loans made to eligible borrowers which minimizes the level of credit risk associated with these loans.
Total non-interest income in the fourth quarter of 2021 decreased by $40,000, or 0.9%, from the prior year's fourth quarter, but increased by $1.5 million, or 9.1%, for the full year of 2021 when compared to 2020. Wealth management fees increased by $372,000, or 14.4%, in the fourth quarter of 2021 and by $1.8 million, or 17.4%, for the full year of 2021 compared to the same time periods in 2020. The entire wealth management group has performed exceptionally well through the pandemic, actively working for clients to increase the value of their holdings in the financial markets and adding new business. The fair market value of wealth management assets improved since the third quarter of 2021 and totaled $2.7 billion and also increased from the early pandemic fair market value low point on March 31, 2020 by $728.7 million, or 36.7%. Other income improved by $32,000, or 5.0%, for the quarter and also increased by $291,000, or 12.7%, for the full year when compared to 2020 primarily due to higher interchange fee income that resulted from increased usage of debit cards as the pandemic caused consumers to increase online purchases and many businesses to implement contactless services by not accepting cash due to health safety concerns. Service charges on deposit accounts increased during the fourth quarter by $45,000, or 19.1%, and by $62,000, or 6.9%, for the full year as consumers are more active and increasing their spending habits in 2021. Revenue from bank owned life insurance was relatively stable quarter over quarter but increased by $335,000, or 42.8%, for the year due to the receipt of an additional death claim as well