Cleaning office (some) and found the following.
From a minor pension for the few that managed to get to old age, to an entitlement expected after a rather brief working career (say from 25 to 64) compared to ones youth and life expediency (into the 80's and lengthening)
Ageing in the rich world: The end of retirement | The Economist:
"Now retirement is for everyone, and often as long as whole lives once were. In some European countries the average retirement lasts more than a quarter of a century. In America the official pension age is 66, but the average American retires at 64 and can then expect to live for another 16 years. Average spending on public pensions across the OECD is now the equivalent of more than 7% of GDP (they cost America just 0.2% back in 1935). In some countries the current figure could double by 2050, to say nothing of the cost of private pensions and extra spending on health and long-term care."