September 30, 2021 to $40,109 for the six months ended September 30, 2022, primarily due to higher spot rates despite higher bunker prices. The Baltic Exchange Liquid Petroleum Gas Index, an index published daily by the Baltic Exchange for the spot market rate for the benchmark Ras Tanura-Chiba route (expressed as U.S. dollars per metric ton), averaged $71.290 during the six months ended September 30, 2022 compared to an average of $47.303 for the six months ended September 30, 2021. The average price of very low sulfur fuel oil (expressed as U.S. dollars per metric ton), from Singapore and Fujairah increased from $525 during the six months ended September 30, 2021, to $899 during the six months ended September 30, 2022. Our fleet utilization decreased from 95.9% during the six months ended September 30, 2021 to 93.3% during the six months ended September 30, 2022.
Charter Hire Expenses
Charter hire expenses for the vessels chartered in from third parties were $10.8 million and $5.9 million for the six months ended September 30, 2022 and 2021, respectively. The increase of $4.9 million, or 82.0%, was mainly caused by an increase in the number of chartered-in days from 230 for the six months ended September 30, 2021 to 366 for the six months ended September 30, 2022.
Vessel Operating Expenses
Vessel operating expenses were $34.6 million during the six months ended September 30, 2022, or $9,460 per vessel per calendar day, which is calculated by dividing vessel operating expenses by calendar days for the relevant time-period for the technically-managed vessels that were in our fleet. The decrease of $4.1 million, or 10.6% from $38.7 million for the six months ended September 30, 2021 was due to a reduction of calendar days for our fleet from 4,003 during the six months ended September 30, 2021 to 3,660 during the six months ended September 30, 2022, driven by the sales of Captain Markos NL and Captain Nicholas ML prior to the six months ended September 30, 2022. The decrease of $211 per vessel per calendar day, from $9,670 for the six months ended September 30, 2021 to $9,460 per vessel per calendar day for the six months ended September 30, 2022 was partly the result of a $0.9 million, or $226 per vessel per calendar day, decrease in non-capitalizable operating expenses related to the drydocking of vessels. Adjusting for the non-capitalizable drydocking costs, vessel operating expenses per vessel per calendar day increased very modestly by $15 during the six months ended September 30, 2022.
General and Administrative Expenses
General and administrative expenses were $17.6 million for the six months ended September 30, 2022, an increase of $0.2 million, or 1.1%, from $17.4 million for the six months ended September 30, 2021. This increase was driven by $0.6 million in financial support for the families of our Ukrainian and Russian seafarers affected by the events in Ukraine and increases of $0.5 million and $0.2 million in stock-based compensation and other general and administrative expenses, respectively, for the six months ended September 30, 2022. This was partially offset by a reduction in employee-related expenses of $1.1 million for the six months ended September 30, 2022.
Interest and Finance Costs
Interest and finance costs amounted to $20.0 million for the six months ended September 30, 2022, an increase of $8.8 million, or 78.1%, from $11.2 million for the six months ended September 30, 2021. The increase of $8.8 million during this period was mainly due to increases of $4.3 million in interest incurred on our long-term debt, $3.5 million in accelerated amortization of financing costs resulting from the repayment of the 2015 AR Facility and long-term debt on Concorde and Corvette, and $0.9 million in loan expenses driven by an increase in average indebtedness, excluding deferred financing fees, from $593.6 million for the six months ended September 30, 2021 to $695.1 million for the six months ended September 30, 2022. Average interest rates increased on our long-term debt due to rising SOFR on our floating-rate long-term debt. The increase in average indebtedness is due to the 2022 Facility refinancing during the six months ended September 30, 2022. As of September 30, 2022, the outstanding balance of our long-term debt, net of deferred financing fees of $6.6 million, was $642.0 million.