Box 9b: Structural Ageing (percentage change)
For many purposes it is important to express change over time as a percentage rather than a raw number. The accompanying graph uses the same data as in Box 9a, but with the change for each age group expressed as a percentage of the present number at that age. However the overall description remains the same. If Tasmania experiences consistent annual net migration gains of 940 and a birth rate of 2.08 (the Series B assumptions), along with continued but slowing inprovements in life expectancy, between now and 2018 the total population will grow by around 6.7 per cent (33,573 people). However virtually all of that growth will occur at the older ages. At ages 65+ the increase would be 38 per cent, while for all other age groups combined it would be 1.2 per cent. Similarly between 2008 and 2028, the Series B assumptions indicate total population growth of some 11.8 per cent (58,557 people); at age 65+ this would be 78 per cent, while all other age groups combined would be zero.
Over the next decade (2008-2018), growth at the older ages 62-81 years will range between 20 and 70 per cent, while between 2008 and 2028 it will surpass 80 and 90 per cent for many age groups, with those aged 81 years projected to more than double.
The outcome of these structural shifts will see those aged 65+ years increase from their current 15.0 per cent share of the total population, to around 27 per cent by 2056 (Series B). This proportion will continue to grow until well into the second half of the century - it will only begin to decline when the large baby boom 'echo' cohorts born around 1970 (now around 35 years of age) reach very old age (see also Box 16).