AU has the longest supply chain of any IEA member. Distance — not just shortfall % — is what makes Australia uniquely exposed. A mild disruption at a distant refinery compounds against weeks of product-tanker transit before fuel reaches Botany or Geelong.
National average masks state-level disparity: states depend on different source refineries, so a national X% shortfall can mean much larger hits in states tied to the most-disrupted sources and smaller hits elsewhere. The national line is the headline, not the worst case.
Station-level cascade front-loads outages: metros with fewer stations per capita deplete first, and regions can run dry while neighbouring postcodes still have fuel. National averages smooth over the cascade — the first visible outages come days before the national line would suggest.