Rotterdam Bunker Data: Respect Units and Subtotals

Key takeaways

• Preserve each published category's unit and observation period.
• Read the subtotal notes before reconstructing an aggregate.
• Distinguish a mass share from an energy, value or emissions comparison.
• Use market activity as context, then confirm the actual procurement proposition.

Rotterdam's published table illustrates the unit issue

Rotterdam's bunker-sales table reports several fuels in tonnes and LNG in cubic metres; its notes specify an LNG conversion for the subtotal. Port of Rotterdam bunker-sales table

Those distinctions matter before any calculation begins. A spreadsheet that simply sums the displayed column values may produce an aggregate with no consistent physical meaning. The published method should remain visible wherever the desk reproduces or analyses the series.

For a current transaction, the monitoring dataset reference is not provided; obtain current verified information. Record the verified release, observation period, category units and relevant methodology note. Do not fill the field with an unverified current total.

Choose the question before choosing the denominator

A buyer may want to understand recorded sales activity, its own purchasing mix or the relative use of different fuel categories. These questions need clearly defined comparisons rather than one universal market-share number.

A mass-based share answers a different question from an energy-based share. Neither automatically establishes the monetary value of the purchases or their emissions treatment. Keep the measure's name and denominator explicit.

If the available public table does not provide the basis needed for the intended question, report the limitation. Do not create unsupported conversion assumptions to make the dataset answer something outside its scope.

Keep published and buyer-specific conversions separate

A statistical conversion used to produce a port subtotal is part of that publication's methodology. It is not automatically the appropriate basis for an invoice, a vessel requirement or a particular product's commercial quantity conversion.

For a transaction, obtain the relevant supported inputs and responsible review. Preserve them in the purchase record rather than copying a convenient factor from a market table.

The same discipline applies when comparing fuel cost. A price per tonne and a price per another unit cannot be ranked directly without a defined, relevant normalisation. The statistical table can describe market activity without resolving that procurement calculation.

A dataset-reading matrix

The matrix makes the limitations part of the analysis rather than a footnote added after a misleading chart has been produced.

Watch for category and period changes

Before comparing releases, confirm that the headings and explanatory notes are compatible. A table can be updated with another period, revised figures or a different presentation. Retain the release reference used for the analysis so the result can be reproduced.

Do not compare an incomplete reporting interval with a complete one without explaining the difference. Likewise, distinguish a quarterly movement from an annual comparison instead of choosing whichever percentage creates the strongest narrative.

Where a source revises earlier observations, note whether the desk's previous report needs refreshing. A changed historical number is not necessarily a new event in the current market.

Fictional case: a plausible total with mixed units

A fictional Rotterdam procurement analyst downloads a bunker-sales table and sums every visible fuel column to create a portfolio chart. The resulting total looks plausible, so the analyst calculates category shares and circulates a market note.

A reviewer checks the headings and discovers that one column uses a different physical unit. The team rebuilds the analysis using the publication's stated aggregate method where appropriate and labels the resulting measure clearly.

For a separate vessel purchase, the team obtains transaction-specific quantity evidence rather than reusing the table's statistical conversion. The same source remains useful for market context, but it is no longer asked to determine an individual invoice or fuel requirement.

Turn the observation into a useful enquiry

A change in a relevant category may justify asking suppliers about the current product and delivery proposition. It does not prove that the next call will encounter shortage, surplus or a particular price direction.

The monitoring note should identify the observed period, the supported finding and the next procurement question. Keep current supplier quotations and their validity separate from the historical data series.

If the desk cannot establish a clean comparison, a concise statement of that limitation is better than a precise but unsupported ranking. The purpose of monitoring is to improve the purchase decision, not to maximise the number of calculated percentages.

Common mistakes

Do not sum tonnes and cubic metres directly or reuse a statistical factor as a transaction instruction. Other errors include confusing mass share with energy share, comparing incompatible periods and treating a bio-blend category as proof of an emissions result. A plausible chart can still rest on an invalid denominator.

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