loans of $14.3 million, or 60.2%, recreational vehicle loans of $13.3 million, or 5,070.6%, commercial business loans of $13.0 million, which includes $10.0 million of PPP loans, or 89.8%, other consumer loans of $2.2 million, or 105.4%, and automobile loans of $921,000, or 4.4%, offset in part by decreases in one- to four-family residential real estate loans of $7.6 million, or 5.5%, and nonresidential loans of $8.4 million, or 23.5%. Net deferred fees increased $5.6 million, or 114.8%, during the nine months ended September 30, 2020, representing primarily fees paid for purchased loans which are amortized over the estimated loan lives.
Consistent with our business strategy, we intend to continue to increase the purchase and origination of automobile, recreational vehicle and manufactured home loans. During the nine months ended September 30, 2020, we purchased $7.6 million of automobile loans, $13.5 million of recreational vehicle loans and $17.5 million of manufactured home loans. Additionally, to supplement originations, we intend to begin purchasing one- to four-family residential real estate loans.
Investment Securities. Securities available-for-sale decreased $7.5 million, or 24.5%, to $23.1 million at September 30, 2020 from $30.6 million at December 31, 2019. The decrease in securities available-for-sale resulted from the sale of $8.8 million of municipal bonds, partially offset by purchases of $1.1 million of municipal bonds and a $523,000 increase in unrealized gains.
Equity investment securities, which are comprised of mutual funds invested in preferred stock and municipal bonds and equity securities held in a directors’ retirement plan rabbi trust decreased $2.0 million, or 77.0%, to $594,000 at September 30, 2020 from $2.6 million at December 31, 2019 as a result of management’s decision to sell the mutual funds to eliminate the volatility of changing market prices.
Premises and Equipment. Premises and equipment decreased $642,000, or 3.7%, to $16.9 million at September 30, 2020 from $17.6 million at December 31, 2019. The decrease resulted primarily from recognition of depreciation expense of $795,000.
Pension Plan Assets. Pension plan assets increased $835,000, or 11.0%, to $8.4 million at September 30, 2020 from $7.6 million at December 31, 2019. The increase resulted from estimated returns on pension assets of $1.3 million and employer contributions of $281,000, offset by estimated benefits paid of $330,000 and interest costs of $443,000.
Deposits. Deposits increased $20.0 million, or 7.1%, to $303.4 million at September 30, 2020 from $283.3 million at December 31, 2019. Noninterest-bearing deposits increased $13.7 million, or 36.1%, to $51.9 million at September 30, 2020 from $38.1 million as of December 31, 2019. Interest-bearing accounts increased $6.3 million, or 2.6%, to $251.5 million at September 30, 2020 from $245.2 million at December 31, 2019. Interest-bearing checking accounts increased $4.9 million, or 17.8%, to $32.4 million at September 30, 2020 from $27.5 million at December 31, 2019. The largest increase in interest-bearing deposits was in savings accounts which increased $19.9 million, or 23.4%. Additionally, money market accounts increased $794,000, or 3.2%, to $25.7 million at September 30, 2020 from $24.9 million at December 31, 2019 and certificates of deposit decreased $19.4 million, or 18.0%, to $88.2 million at September 30, 2020 from $107.6 million at December 31, 2019.
Municipal deposits held at Generations Commercial Bank totaled $43.5 million at September 30, 2020 and at December 31, 2019. Also, in light of the current historically low interest rate environment, in October 2020 we allowed a significant amount of municipal deposits to roll off at maturity without bidding for these ongoing relationships.
Federal Home Loan Bank Advances. Federal Home Loan Bank advances decreased $1.4 million, or 4.4%, to $30.1 million at September 30, 2020 from $31.4 million at December 31, 2019. The average cost of outstanding advances from the Federal Home Loan Bank was 2.11% at September 30, 2020, compared to our weighted average rate on deposits of 0.82% at that date.
Subordinated Debt and Other Borrowings. Subordinated debt and other borrowings increased $500,000, or 68.0%, to $1.2 million at September 30, 2020 from $735,000 at December 31, 2019. In July 2020, we obtained $500,000 of