Premise: The 1989 Newcastle earthquake occurred in Newcastle, New South Wales on Thursday, 28 December. The shock measured 5.6 on the Richter magnitude scale and was one of Australia's most serious natural disasters, killing 13 people and injuring more than 160. The damage bill has been estimated at A$ 4 billion (including an insured loss of about $1 billion).
Hypothesis: The earthquake occurred prior to 1990.