The world steel Association has reported a 6% increase in global pig production for the first quarter, with China leading the charge with a year over year increase of 8%.
Excluding China the rest of the world grew at a more moderate pace of 2%.
On one side, you have non Australian premium hard coking coals imported into China benefiting from a stable and elevated CFR base index price that was range bound between 214 and $223 per metric ton for most of the first quarter.
We saw the Australian index price climb from its low of $102 per metric ton at the start of the year, and peak at a high of $161 per metric ton in late January.
At this point, the price started its gradual decline, hitting its low of $110 per metric ton in late March.
sales volume in the first quarter was 2 million short tons compared to 1.8 million short tons in the same quarter last year.
Our sales by geography for the fourth quarter were 30% into Europe 14% into South America, and 56% into Asia.
production volume in the first quarter of 2021 was 2.2 million short tons, compared to a similar amount in the same quarter of last year.
As planned and previously communicated, inventories remained elevated at the end of the first quarter compared to pre pandemic levels, call inventory levels increased to 220,004 times to 1.2 million short times at the end of the first quarter.
Our gross price realization for the first quarter of 2021 was 95% of the Platts premium lowball fob Australian index price and was higher than the 89% achieved in the prior year period.
Or better gross price realization was primarily due to a higher percentage of our sales to Chinese customers that the CFR index price or spot sales volume in the first quarter was approximately 48% of total volumes, compared to a normal expectation of approximately 20%.
The company record a net loss on a GAAP basis of approximately $21 million, or a loss of 42 cents per diluted share, compared to net income of $22 million or 42 cents per diluted share in the same quarter last year.
Non GAAP adjusted net income for the first quarter, excluding that non cash charge for Tax Valuation allowance was eight cents per diluted share, compared to 39 cents per diluted share in the same quarter of 2020.
Justin EBITDA was $47 million in the first quarter of 2021 as compared to $62 million in the same quarter last year.
The quarterly decrease was primarily driven by a 13% decrease, in average net selling prices partially offset by higher sales volume.
Our adjusted EBITDA margin was 22% in the first quarter of 2021, compared to 27% in the same quarter last year.
revenues were approximately $214 million in the first quarter of 2021, compared to $227 million in the same quarter last year.
This decrease was primarily due to the 13% decrease in average net selling prices, partially offset by an 8% increase in sales volume in a weak price environment as was noted earlier.
The Platts premium lowball fob Australian index price average $28 per metric ton lower or down 18% in the first quarter of 2021.
Compared to the same quarter last year, the index price averaged $127 per metric ton for the quarter.
The merge and other charges reduced our gross price realization to an average net selling price of $106 per short term in the first quarter of 2021, compared to $122 per short term in the same quarter last year.
cost of sales was $154 million, or 75% of mining revenues in the first quarter, compared to $152 million, or 68% of mining revenues in the same quarter of 2020.
The slight increase in total dollars was primarily due to higher sales volume, offset by lower variable cost and a focus on controlling cost of sales per short ton fob port was approximately $79 in the first quarter compared to $83 in the same period of 2020.
$79 per short ton, was our second lowest quarterly amount in the last four years.
tissue, the expenses were about $8 million, or 3.6% of total revenues in the first quarter of 2021.
And we're 10% lower than the same quarter last year, primarily due to lower professional fees and employee related expenses.
depreciation depletion expenses for the first quarter of 2021, with $33 million, compared to $29 million in last year's quarter.
The interest expense was about $9 million in the first quarter and included interest on our outstanding debt plus amortization of our debt issuance costs associated with our credit facilities, partially offset by interest income.
This was approximately $1 million higher compared to the same period last year, primarily due to incremental borrowings on our abl facility and lower returns on cash balances.
We record an income tax expense of $24 million during the first quarter of 2021, compared to inexpensive $3 million in the same quarter last year.
And therefore the value of our state net operating losses have been written down to cash flow in the first quarter of 2021, we generate $23 million in positive free cash flows, which resulted from cash flows provided by operating activities the $45 million less cash used for capital expenditures in mind development cost of $22 million.
pressures and invest investing activities for capital expenditures and mine development costs were $22 million during the first quarter of 2021, compared to $26 million in the same quarter last year.
The company spent $13 million per 58% less on capex in the first quarter of 2021 compared to the same period last year, which was largely offset by higher spending on mine development cost.
Cash Flows used by financing activities were $13 million in the first quarter of 2021 and consisted primarily of payments for capital leases of $8 million in the payment of a quarterly dividend of $3 million.
Balance Sheet remains strong with a leverage ratio of 2.4 times adjusted e but we believe our liquidity is adequate to navigate these uncertain times.
Total available liquidity at the end of the first quarter was $272 million consisting of cash and cash equivalents of $222 million with $50 million available under a abl facility which is net of borrowings of $40 million and now saying letters of credit for approximately $9 million.
We have delayed the development of the blue Creek project, and our stock repurchase program also remains temporarily suspended.
We believe that we are well positioned to fill our customer volume commitments for 2021 of approximately 4.9 to 5.5 million short tons through a combination of existing coal inventory of 1.2 million short tons and expected production during the rest of the year.
And the plans may vary significantly from quarter to quarter in 2021.

Summary:
We have delayed the development of the blue Creek project, and our stock repurchase program also remains temporarily suspended.
And the plans may vary significantly from quarter to quarter in 2021.