A4. Population reduction in the past and future. Causes not ceased, understood nor reversible.

An observed, estimated, inferred, projected or suspected population reduction where the time period must include both the past and the future (up to a max. of 100 years in future), and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible. CR = greater than or equal to 80%. EN = greater than or equal to 50%. VU = greater than or equal to 30%.