Farmers maintains, in the opinion of management, liquidity sufficient to satisfy depositors’ requirements and meet the credit needs of its customers. The Company’s non-brokered deposits increased 17% from $2.4 billion at June 30, 2020 to $2.8 billion at June 30, 2021. As a result of the large increase in deposits, the loan to deposit ratio at June 30, 2021 stands at 70.5%, a significant decrease compared to 88.1% one year ago. The Company has additional borrowing capacity at the Federal Home Loan Bank of Cincinnati and approved lines of credit at two domestic banks.
Non-performing assets to total assets remains at a low level, currently at 0.43% which is the same ratio reported one year ago. Early stage delinquencies, defined as 30-89 days past due, were $7.6 million, or 0.39% of total loans, at June 30, 2021, compared to $10.3 million, or 0.43% of total loans, for the quarter ended June 30, 2020. Net charge-offs for the current quarter were $179 thousand, compared to $392 thousand in the same quarter in 2020. Total net charge-offs as a percentage of average net loans outstanding is 0.04% for the quarter ended June 30, 2021, down 0.04% compared to the same quarter in 2020.
As a result of improved factors that exist in the current economic environment as well as the decrease in the loan portfolio when compared to prior quarters, the Company was able to decrease its provision for credit losses to $50 thousand for the quarter ended June 30, 2021, compared to the $425 thousand recorded in the first quarter of this year. As an overall percentage of loans, the allowance for credit losses increased to 1.27% for the current quarter compared to 1.22% for the quarter ended March 31, 2021. Excluding the PPP loans, this allowance for credit losses to gross loans ratio increased to 1.33% (non-GAAP) as of June 30, 2021, and the ratio of the allowance for credit losses to gross loans, excluding PPP loans and acquired loans is 1.52% (non-GAAP).
The net interest margin for the three months ended June 30, 2021 was 3.54%, a 20 basis points decrease from the quarter ended June 30, 2020, and 4 basis points less than the 3.58% reported for the linked quarter. In comparing the second quarter of 2021 to the same period in 2020, asset yields decreased 56 basis points, while the cost of interest-bearing liabilities decreased 49 basis points. Most of the decrease in the asset yields was the result of lower rates earned on taxable and tax-exempt securities. Each of the major interest-bearing liability categories experienced cost decreases compared to one year ago. The net interest margin for the quarter ended June 30, 2021 excluding interest and fees from PPP loans would decrease the margin by 12 basis points (non-GAAP). The net interest margin is also impacted by the additional accretion as a result of the discounted loan portfolios acquired in previous mergers, which increased the net interest margin by 4 basis points for the quarter ended June 30, 2021 and 5 basis points for the quarter ended June 30, 2020.
Noninterest income increased 8.1% to $9.9 million for the quarter ended June 30, 2021 compared to $9.1 million in the same quarter in 2020. The Company’s wealth management businesses led the improvement as trust fee income increased $506 thousand, or 27.32%, insurance agency commissions increased $267 thousand, or 39.2% and investment commissions increased $219 thousand, or 72%. Other improvements noted include debit card interchange fees increasing $259 thousand, or 26.78%, and other operating income increasing $471 thousand, or 141%. Those increases were offset by a $1.2 million, or 31.66%, decrease in gain on sale of mortgage loan income resulting from a slowdown in the level of mortgage loan refinancing.
Farmers has remained committed to managing the level of noninterest expenses. Total noninterest expenses for the second quarter of 2021 decreased 1.72% to $17.4 million compared to $17.7 million in the same quarter in 2020. This was primarily a result of decreases in telephone and data communication costs of $209 thousand, or 60.06%, core processing charges of $103 thousand, or 11.03%, advertising expense of $126 thousand, or 39.13%, and FDIC insurance of $105 thousand, or 46.67%. These decreases were offset by increases of $215 thousand, or 12.84%, in occupancy and equipment expense and $153 thousand, or 1.58%, in salaries and employee benefits. Annualized noninterest expenses excluding acquisition costs (non-GAAP) measured as a percentage of quarterly average assets improved from 2.50% in the second quarter of 2020 to 2.12% in the second quarter of 2021.
The efficiency ratio for the quarter ended June 30, 2021 improved to 46.14% compared to 50.75% for the same quarter in 2020. The increases in several categories of noninterest income and net interest income, accompanied with lower noninterest expenses were the main drivers of the improvement.