Over the past decade and a half there has been a significant decline in the share of people over 55 reporting that they have such an impairment. This improvement in health is allowing people to stay in the workforce longer. Greater acceptance of flexible work practices is also supporting this change.
https://www.rba.gov.au/speeches/2018/sp-gov-2018-08-08.html  11/18  8/8/2018  Demographic Change and Recent Monetary Policy | Speeches | RBA  Graph 11  A related development is the ongoing shift in economic activity towards service industries, which tend to be less physically demanding on the body. On average, labourers have one of the youngest retirement ages and managers and professionals have the oldest retirement ages (Graph 12).