Fee income, as an annualized percentage of average total finance receivables, decreased 9 basis points to 1.69% for thesix-month period ended June 30, 2018 from 1.78% for thesix-month period ended June 30, 2017. Late fees remained the largest component of fee income at 1.03% as an annualized percentage of average total finance receivables for thesix-month period ended June 30, 2018, compared to 1.07% for thesix-month period ended June 30, 2017. As an annualized percentage of average total finance receivables, net residual income was 0.39% for thesix-month period ended June 30, 2018, compared to 0.44% for thesix-month period ended June 30, 2017.
Interest expense increased $2.1 million to $7.1 million, or 1.70% as an annualized percentage of average deposits, for thesix-month period ended June 30, 2018, from $5.0 million, or 1.34% as an annualized percentage of average deposits, for thesix-month period ended June 30, 2017. The increase was primarily due to an increase in the rate paid on interest bearing liabilities and to a lesser degree, the increase in the average balances of interest bearing liabilities. Interest expense, as an annualized percentage of average total finance receivables, increased 33 basis points to 1.54% for thesix-month period ended June 30, 2018, from 1.21% for the corresponding period in 2017. The average balance of deposits was $837.6 million and $742.8 million for the six-month periods ended June 30, 2018 and June 30, 2017, respectively.
There were no borrowings outstanding for each of thesix-month periods ended June 30, 2018, and June 30, 2017.
Our wholly-owned subsidiary, MBB, serves as our primary funding source. MBB raises fixed-rate and variable-rate FDIC-insured deposits via the brokered certificates of deposit market, on a direct basis, and through the brokered MMDA Product. At June 30, 2018, brokered certificates of deposit represented approximately 62% of total deposits, while approximately 35% of total deposits were obtained from direct channels, and 3% were in the brokered MMDA Product.
Insurance premiums written and earned.Insurance premiums written and earned increased $0.4 million to $3.9 million for thesix-month period ended June 30, 2018, from $3.5 million for thesix-month period ended June 30, 2017, primarily due to an increase in the number of contracts enrolled in the insurance program as well as higher average ticket size.
Other income. Other income was $5.9 million and $4.4 million for thesix-month periods ended June 30, 2018 and June 30, 2017, respectively. Other income primarily includes various administrative transaction fees and fees received from referral of leases to third parties, and gain on sale of leases and servicing fee income, recognized as earned. Selected major components of other income for thesix-month period ended June 30, 2018 included $0.5 million of referral income, $1.0 million of insurance policy fees, and $3.8 million gain on the sale of leases and servicing fee income. In comparison, selected major components of other income for thesix-month period ended June 30, 2017 included $1.7 million of referral income, $0.9 million of insurance policy fees, and $1.1 million gain on the sale of leases and servicing fee income.
Salaries and benefits expense.Salaries and benefits expense increased $1.1 million, or 5.9%, to $19.6 million for thesix-month period ended June 30, 2018 from $18.5 million for the corresponding period in 2017. The increase was primarily due to increased compensation related to increased salaries and bonus as well as increased commission on higher origination volume. Salaries and benefits expense, as an annualized percentage of average total finance receivables, was 4.23% for thesix-month period ended June 30, 2018 compared with 4.52% for the corresponding period in 2017.
Total personnel decreased to 320 at June 30, 2018 from 329 at June 30, 2017.
General and administrative expense.General and administrative expense decreased $3.3 million, or 20.2%, to $13.0 million for thesix-month period ended June 30, 2018 from $16.3 million for the corresponding period in 2017. General and administrative expense as an annualized percentage of average total finance receivables was 2.82% for thesix-month period ended June 30, 2018, compared to 3.99% for thesix-month period ended June 30, 2017. Selected major components of general and administrative expense for thesix-month period ended June 30, 2018 included $1.8 million of premises and occupancy expense, $1.0 million of audit and tax compliance expense, $1.8 million of data processing expense, $1.0 million of marketing expense, and $1.1 million of amortization expense. In comparison, selected major components of general and administrative expense for thesix-month period ended June 30, 2017 included $1.7 million of premises and occupancy expense, $0.8 million of audit and tax compliance expense, $1.6 million of data processing expense, and $1.0 million of marketing expense, and $0.7 million of insurance-related expenses and a $4.2 million estimated charge for restitution expense in connection with MBB’s regulatory examination preliminary findings (See Note 9, Commitments and Contingencies, in the accompanying Notes to Consolidated Financial Statements).
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