Comparing the three months ended March 31, 2018, to the three months ended March 31, 2019, mutual fund distribution expense decreased by 13.8%, from $0.12 million to $0.11 million. Although the dollar value of mutual fund distribution expense decreased, as a percentage of total revenue, mutual fund distribution expense increased 0.1 percentage points to 1.0%.
Comparing the six months ended March 31, 2018, to the six months ended March 31, 2019, mutual fund distribution expense decreased by 5.8%, from $0.24 million to $0.23 million. Although the dollar value of mutual fund distribution expense decreased, as a percentage of total revenue, mutual fund distribution expense increased 0.1 percentage points to 1.0%.
In both periods, the dollar value decrease was due to lower average daily net assets held by financial institutions.
Sub-Advisory Fees Expense: Comparing the three months ended March 31, 2018, to the three months ended March 31, 2019,sub-advisory fees expense decreased by 15.0%, from $2.6 million to $2.3 million. Although the dollar value ofsub-advisory fees expense decreased, as a percentage of total revenue,sub-advisory fees expense increased 2.6 percentage points to 21.5%.
Comparing the six months ended March 31, 2018, to the six months ended March 31, 2019,sub-advisory fees expense decreased by 9.4%, from $5.2 million to $4.7 million. Although the dollar value ofsub-advisory fees expense decreased, as a percentage of total revenue,sub-advisory fees expense increased 2.6 percentage points to 21.2%.
In both periods, the dollar value decrease resulted from decreased average daily net assets of thesub-advised Hennessy Funds, partially offset by fee increases resulting from the amendment to thesub-advisory agreement for the Japan Fund and the Japan Small Cap Fund that became effective February 28, 2018, and the newsub-advisory relationship with BP Capital for the Hennessy BP Energy Fund and the Hennessy BP Midstream Fund.
Depreciation Expense: Comparing the three months ended March 31, 2018, to the three months ended March 31, 2019, depreciation expense decreased by 6.9%, from $0.06 million to $0.05 million. Although the dollar value of depreciation expense decreased, as a percentage of total revenue, depreciation expense increased 0.2 percentage points to 0.6%. The dollar value decrease was a result of a lower fixed asset base.
Comparing the six months ended March 31, 2018, to the six months ended March 31, 2019, depreciation expense increased by 3.8%, from $0.105 million to $0.109 million. As a percentage of total revenue, amortization and depreciation expense increased 0.1 percentage points to 0.5%. The increase was a result of a higher fixed asset base.
Interest Expense
Comparing the three months ended March 31, 2018, to the three months ended March 31, 2019, interest expense remained approximately the same at $0.30 million.
Comparing the six months ended March 31, 2018, to the six months ended March 31, 2019, interest expense increased by 1.2%, from $0.60 million to $0.61 million. The increase was due primarily to an increase in the interest rate charged to our loan, partially offset by a decrease in the principal balance on our loan.
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